Given the lack of details when it comes to their relationship, it is kind of impossible to say anything for sure. However, at one point during the Theogony Hesiod describes Rhea as tamed/subjected/subdued (δμηθεῖσα) by Kronos, the same verb used in the poem to describe Thetis' marriage with Peleus (which is a forced one in the overwhelming majority of sources) and of Medea with Jason (again a union arranged by the gods), as well as Zeus and Herakles overpowering their adversaries.

Now maybe it is a bit of a stretch to assume that this must have involved rape given that the idea of maidens being tamed by men through marriage/sexual union was a common metaphor in ancient Greek literature, but Hesiod uses this expression quite sparingly when describing the matings of gods and other beings so perhaps it does say something about the nature of the relationship.

Regarding the use of δάμνημι in the Theogony, Evelien Bracke says: "My suggestion is that when Hesiod uses this verb in reference to women, the verb is not just an established metaphor that denotes marriage but retains its original force of taming, subduing and subjecting. The actions of gods and men subjecting goddesses and women are seen to be in exact parallel with the actions of gods and men who overcome their opponents in other contexts. Eros, for example, subjects (δάμναται, 120-122) the minds of gods and men, Heracles overcomes (ἐδάμασσε, 330-332) the Nemean lion, and Zeus overpowers both Cronus (δαμῆναι, 463-465) and Typhoeus (δάμασεν, 857-858). The verb is here used to denote the violent conquest of opponents." (Narrative Manipulation of Medea and Metis in Hesiod's Theogony)

And Rebecca Symonds states the following: "His [Kronos's} violent streak manifests again in his union with Rhea who is ‘overpowered’ by him: Ῥείη δὲ δμηθεῖσα Κρόνῳ τέκε φαίδιμα τέκνα. 308 The use of the term ‘overpowered’ is significant. Whilst there is no rigid definition of a sexual assault within ancient Greek culture there is an understanding that violence or force can be used to overpower a woman and that this is not a positive use of strength. The only other male figures who overpower their wives within the Theogony are Hyperion, Orthos and Peleus. Whilst it cannot be ignored that different cultures have different attitudes regarding issues of consent, the context of these situations demonstrates that the use of overpowering force is not viewed positively. The union of Peleus and Thetis is an infamously unhappy one, as the goddess, resenting her marriage to a mortal and the grief it will cause her, resides in the ocean away from her husband. Orthos is described as the dog child of Echidna and Typhon who mates with his equally monstrous sister Chimaira to produce both the Sphynx and the Nemean Lion. The offspring of this union are devastating to humanity until they are eventually defeated by heroes. The one exemption to this would seem to be Hyperion who overpowers Theia in love, which could imply a less violent nature to his advances. This small but important distinction is missing in Kronos’ advances on Rhea. The male figures who are associated with ‘overpowering’ their partners are few in number and the instances that they describe can be predominantly characterised as negative. The limited number of figures suggests that this is a term being used in a specific context and carries a meaning deeper than simply an alternative linguistic choice." (The Power Dynamics of the Family of the Gods in Archaic Verse)

But to demonstrate how futile is to try to definitively find the presence or absence of consent in most sexual encounters in ancient Greek literature where no further context is provided (and especially in a work like Hesiod's in which consent to sex or lack thereof is very much not the point), elsewhere in the Theogony the word used to describe Kronos and Rhea's mating is philotes, like so many other unions in the poem: ἀλλά σφεας Κρονίδης τε καὶ ἀθάνατοι θεοὶ ἄλλοι, οὓς τέκεν ἠύκομος Ῥείη Κρόνου ἐν φιλότητι "But the son of Kronos and the other immortal gods, those whom fair-haired Rhea bore in union (philotes) with Kronos" (Hes. Theog. 624-5). You might encounter the idea that a union in philotes implies consent, reciprocity, tenderness and what not, but I'd say that it is highly debatable and we know from instances like Poseidon and Tyro in the Odyssey or Zeus and Nemesis in the Kypria that two people can be joined in philotes through trickery or even force, and from the sex scene between Zeus and Hera in Iliad 14 that philotes need not necessarily be brought about through mutual desire and genuine affection. This post is already too long as it is, so I'll just link to this passage that discusses the concept of philotes in a little more detail.

I feel like I rambled a lot without properly answering the question (this is kind of my thing I guess) and I'm sorry for that, but this is a complicated topic and the truth is that I don't have a proper answer. Let's just say that I think it's possible that he did and I wouldn't find it unreasonable in the slightest for someone to use an interpretation like this. It would make perfect sense to me for a mother who has seen her child(ren) devoured by her partner to be unwilling to bring more children into the world knowing that they will be subjected to the same fate.

The fact that I've read multiple stories based on Greek mythology in which Rhea is killed off really irritates me.

Lmao according to all three Vatican mythographers Rhea saved Zeus from Kronos because he was a cute baby. Tough luck, everyone else, you should have been prettier as newborns I guess.

🤷 It's a thing that exists I guess? I mean, we know nothing about what their relationship was like so I don't really have an opinion. The whole father tries to get rid of his children and mother turns against him thing was already done before them by Gaia and Ouranos (in a cooler/funnier way at that), so they don't have much going for them in the uniqueness department, nor do they interact ever again after Kronos is deposed by Zeus. Even the very little we get to know about their relationship is not particularly appealing, since when relating the union of Kronos and Rhea Hesiod describes her as tamed/subjected/subdued (δμηθεῖσα) by him, the same verb used in the Theogony to describe Thetis' marriage with Peleus (which is a forced one in the overwhelming majority of sources) and of Medea with Iason (again a union arranged by the gods), as well as Zeus overpowering Kronos and Typhoeus and Herakles defeating the Nemean Lion.

The one story of theirs I find intriguing is the one in which they fight and defeat Ophion and Eurynome, the previous rulers of the cosmos. That is pretty cool and unusual.

I don't think anyone would be able to disagree with you on this.

„Upon the Mother depend the winds, the ocean, the whole earth beneath and the snowy seat of Olympos; whenever she leaves the mountains and climbs to the great vault of heaven, Zeus himself, the son of Kronos, makes way, and all the other immortal gods likewise show honour to the dread goddess.” - Apollonios of Rhodes, Argonautica

In my retelling (that is, if I ever were to write one), things differ in several ways from the standard/most popular versions of some myths, but I like to think there is some basis for most changes even if the alternative variants are more obscure or later in date or coming from local traditions, as the ones I've collected in this post.

„When she [Hera] refused to copulate with him [Zeus] because of her mother, the god promised to make her his wife.” (Scholion to Theokritos Idyll 15.64)

This has always intrigued me from the moment I first read it. How are we supposed to interpret Hera's refusal to sleep with Zeus because of their mother?

Does it mean that Hera is uncomfortable with the idea of sleeping with her brother? That does seem unlikely, firstly because incest between gods is perfectly normal and common (we do however have one instance in the Dionysiaca where Aphrodite flees Zeus's sexual advances because he is her father). Secondly, the promise of marriage would seem hardly appropriate because how are her reservations about their biological bond going to disappear if they get married? But again, in this story Zeus specifically approaches Hera using deceptive means and makes sexual advances on her the moment he's managed to get close, so her feelings hardly seem to matter much here.

Or does it mean that Rhea would disapprove of her children hooking up? Again it seems unlikely, considering that Rhea herself was her brother's consort, and if she would not be happy about them sleeping with each other why would she be fine with them marrying?

Could it be that Rhea does not actually have a problem with her children getting together, but simply with Zeus and Hera doing so? Maybe she doesn't think they would make a good couple? Maybe she has different plans for them? But how is them getting married going to fix that? Or is it a case of „let's do it regardless of what mother says”?

Maybe Rhea would simply disapprove of Hera having sex outside marriage regardless of who her partner was, in which case Zeus's promise to make her his wife would actually make sense. But then, why would Rhea impose such restrictions on her daughter when Demeter is free to be unmarried and sexually active?

Or maybe Hera simply doesn't want to have sex with Zeus for whatever reason (she is not physically attracted to him, she doesn't like him as a person, she is not in the mood for sex in that particular moment, she does not like it when someone tries to get her into bed on false pretenses, etc etc) and she is only bringing up their mother because she thinks that he might hesitate to offend Rhea whereas he would have no qualms about offending Hera herself.

So many possible interpretations!

I've talked about this before, but I feel the need to do it again.

It is not that I am a big fan of incest or anything (and they are gods! Why even care about the incest anyway?), but it is actually important that Hera is also the sister and not just the wife of Zeus. It is actually important that she is called “the most glorious child to issue from crafty Kronos and mother Rhea” (Homeric Hymn 5), “eldest/most revered daughter of Kronos” and “august goddess, daughter of great Kronos” (the Iliad), “the supreme celestial goddess, daughter of Kronos” (Pindar Pythian 2). It is not for nothing that Hera emphasises her birth and not just her marriage when talking to Zeus: “And yet my labor must not be rendered worthless; for I too am a god, and my parentage is from the same place as yours, and devious Cronus bore me to be his most revered/eldest (πρεσβυτάτην) daughter. For both these reasons, my birth and also because I am called your wife, and you are lord among all the immortals.” (Iliad IV) or “I—who claim to be the best/noblest (ἀρίστη) of the goddesses, both by birth and because I am called your wife, and you are lord of all the immortals.” (Iliad XVIII).

“It is not possible, nor is it seemly to refuse your request; for you sleep in the arms of almighty Zeus.”, Aphrodite tells Hera in Iliad XIV, but a few lines earlier she also says: “Hera, eldest goddess, daughter of mighty Cronus, speak what you will; my heart compels me to accomplish it, if I am able to accomplish it, and if it can be accomplished.”

To change her parentage because eww, incest! is to diminish her status, to accentuate the already existing power imbalance between her and Zeus even more, and to make her authority depend primarily if not solely on her marriage.

And of course this doesn't just apply to Hera, because family connections are meaningful for all the gods. Demeter is so closely associated with her mother Rhea that they can even be identified with each other. It does say something that Gaia, Rhea and Demeter are some of the only four or so goddesses in Hesiod's Theogony who are given the title “mother”. Persephone was not just some irrelevant flower goddess until Hades made her important and respected, she was the daughter of the king of the gods. To take away their connections (and only theirs; nobody ever seems to change Hades' parentage) just because you are uncomfy with Persephone being married to her uncle is just... weird, not particularly interesting, and certainly not inherently less problematic.

"And then the generation tenth appeared Of mortal men, from the time when the flood Came upon earlier men. And Cronos reigned, And Titan and Iapetus; and men called them Best offspring of Gaia and of Uranus, Giving to them names both of earth and heaven, Since they were very first of mortal men. So there were three divisions of the earth According to the allotment of each man, And each one having his own portion reigned And fought not; for a father's oaths were there And equal were their portions.

But the time Complete of old age on the father came, And he died; and the sons infringing oaths Stirred up against each other bitter strife, Which one should have the royal rank and rule Over all mortals; and against each other Cronos and Titan fought. But Rhea and Gaia, And Aphrodite fond of crowns, Demeter, And Hestia and Dione of fair locks Brought them to friendship, and together called All who were kings, both brothers and near kin, And others of the same ancestral blood, And they judged Cronos should reign king of all, For he was oldest and of noblest form.

But Titan laid on Cronos mighty oaths To rear no male posterity, that he Himself might reign when age and fate should come To Cronos. And whenever Rhea bore Beside her sat the Titans, and all males In pieces tore, but let the females live To be reared by the mother. But When now At the third birth the august Rhea bore, She brought forth Hera first; and when they saw A female offspring, the fierce Titan men Betook them to their homes. And thereupon Rhea a male child bore, and having bound Three men of Crete by oath she quickly sent Him into Phrygia to be reared apart In secret; therefore did they name him Zeus, For he was sent away. And thus she sent Poseidon also secretly away. And Pluto, third, did Rhea yet again, Noblest of women, at Dodona bear, Whence flows Europus' river's liquid course, And with Peneus mixed pours in the sea Its water, and men call it Stygian.

But when the Titans heard that there were sons Kept secretly, whom Cronos and his wife Rhea begat, then Titan sixty youths Together gathered, and held fast in chains Cronos and his wife Rhea, and concealed Them in the earth and guarded them in bonds. And then the sons of powerful Cronos heard, And a great war and uproar they aroused."

- The Sibylline Oracles Book 3

And because I'm all for the strange, unusual, alternative, less common or local variants of myths, here are most of the accounts I know of that deviate more or less strongly from the traditional version of Hesiod where all the children of Kronos except Zeus are devoured at birth and then emerge from Kronos ready to assist their brother in the war:

"It was otherwise, however, with the mates of Uranus and Cronus, who were Gaea, Earth herself, and Rhea. Both were very much present and honored within the dominion of Zeus. In concept, only Zeus could hold paramount sovereignty, but the very foundations of his sovereignty were his maternal nurturers, Gaea and Rhea. They were responsible for bringing Zeus to power, in Hesiod’s account, and we find that they were therefore given honors in cult, especially where Zeus’ sovereignty was also celebrated. At Athens, the close relationship between Gaea, Rhea, Cronus, and Zeus was reflected by the clustering of their sanctuaries beside the Ilissus River at the edge of the city. At Olympia too, Gaea enjoyed cult honors beside Zeus at the foot of the Hill of Cronus. Likewise at Sparta, Gaea and Zeus shared a shrine in the agora. According to the Homeric Hymn to Demeter, Rhea played a decisive role in reconciling her daughter Demeter to her place in the regime of Zeus. It was probably in connection with this role that Rhea received honors, as the Mother at Agrae, in the Lesser Mysteries at Athens. Otherwise, Rhea was chiefly honored in cult at places associated with the deception of Cronus and the birth of Zeus. …

Gaea, “universal mother, eldest of all beings,” was more manifest in this world even than Zeus. As the Homeric Hymn to Earth, Mother of All begins: “She feeds all creatures that are in the world; and all that go upon the bright land, all that go in the ways of the sea, and all that fly, these are fed from her bounty.”70 Because she is omnipresent to all living things, and because all depend on her, Gaea is often named first of all deities as witness and as enforcer of oaths. She is rarely depicted as an active personality among divinities. Impregnated by various forces, she gives birth to Titans, to lesser daemons, ultimately to humankind, and also to monsters that challenge Zeus. Among communities of mortal men, Gaea gave birth to several lines of legendary kings, including Erechtheus or Erichthonius at Athens. Autochthony, or birth from the earth, was a warrant of local legitimacy and localized sovereignty for these ancestral kings and their descendants.

But among the gods, where sovereignty was universal and sovereigns were immortal, succession implied a rupture of legitimacy. Hesiod describes the succession of Cronus over Uranus, and of Zeus over Cronus, as just retribution carried out by the son for the outrageous behavior of his father. Gaea is the one who knows when retribution is due, and can offer counsel to secure its effect or can warn and avert, or postpone, its effect. Gaea secures Zeus’ rise to power and warns him of several threats to his sovereignty. Gaea is thus aware of forces that have the capacity to overthrow even a divine and immortal sovereign. This awareness makes Gaea the original source of prophecy, and she is so represented at Delphi, as Aeschylus describes her at the opening of the Eumenides. Gaea is also the mother of Prometheus, according to Aeschylus, and she is the source of his knowledge that Zeus himself will fall one day."

- The Mother of the Gods, Athens, and the Tyranny of Asia: A Study of Sovereignty in Ancient Religion by Mark H. Munn

“According to Hesiod, (Rhea) went to the Cretan town of Lyktos (to the west of Knossos) when she was due to give birth to Zeus, and entrusted him to her mother Gaia to nourish and rear; so Gaia hid him away deep inside herself in a remote cave on Mt Aigaion (otherwise unknown, but presumably to be identified with one of the various mountains near Lyktos that contain Minoan holy caves). This account is peculiar to the Theogony, for in the subsequent tradition the cave is either located in Mt Ida in the centre of Crete or, less commonly, on Mt Dikte to the east.

Zeus was reared during his infancy by a local nymph or nymphs. In what was perhaps the most favoured tradition, he was tended by the nymph Amaltheia, who fed him on milk from a she-goat that she owned; or in another version which first appears in Callimachus, Amaltheia was the name of the goat itself, and the nymph Adrasteia fed Zeus on its milk along with sweet honeycomb; or else his nurses were Adrasteia and Ida, or the Idaian nymphs Helike and Kynosura, or others of their kind. There were also various picturesque tales in which he was said to have been fed by bees or suckled by a sow or the like. To prevent Kronos from being able to hear the infant’s cries, some minor Cretan divinities, the Kouretes,  danced a noisy war-dance near the entrance to the cave, clashing their spears against their shields. ... Much of this is connected  with ritual, and Cretan ritual at that; excavations have shown that a fair number of cave-sanctuaries in Crete were very ancient holy places dating back to the Minoan period; the dances of the Kouretes can be related to similar dances performed by Cretan youths in initiation rituals and the like; and it seems that a divine child who was born (and probably died) every year was a prominent object of Cretan worship.

A curious tale about Zeus’ cave in Crete is recorded by Antoninus Liberalis in his anthology of transformation myths. The cave (of unspecified location) was inhabited by sacred bees  that had tended the infant Zeus, but was otherwise forbidden ground to gods and mortals alike. At one time four thieves had entered the cave nonetheless to steal some of the honey, wearing full armour (to protect themselves against the bees, and probably on account of its apotropaic value also). When they saw the swaddling-clothes of Zeus, however, and the  blood that had been shed at his birth, their armour fractured and fell from their bodies; and Zeus would have killed them with a thunderbolt as punishment for their sacrilege if the Moirai (Fates) and Themis (as guardian of divine law) had not restrained him by reminding him that no one could be allowed to die in a place of such sanctity. So he transformed  them into various birds that bore the same names as themselves (Laios, Kerkeos, Kerberos and Aigolios). The author remarks that the blood inside the cave used to boil up at a particular time every year, presumably on the anniversary of Zeus’ birth, causing a mass of flame to issue from the cave.

The astronomical literature also provides some odd tales about Zeus’s childhood. In one such story, the nanny-goat that nursed the infant Zeus is said to have been a wondrous child of the sun-god Helios that so alarmed the Titans, apparently because of its radiant brightness, that they asked Earth to conceal it from their view in one of her caves in Crete. When Zeus came of age and was preparing for his war against the Titans, he learned that he would be victorious if he used the hide of the goat as a shield (i.e. as his aigis); and after he duly won his victory, he covered the bones of the goat with another skin, revived it and made it immortal, and placed it in the heavens as Capella (the Goat), a bright star in the constellation of the Charioteer (Auriga). Or in another tale of the kind, Kronos set off in search of Zeus and arrived in Crete, but was deceived by his son, who concealed his presence by transforming himself into a snake and his two nurses into bears. Zeus later commemorated the incident by placing images of the three animals in the sky as the constellations of the Dragon and the Greater and Lesser Bear (Draco and Ursa Major and Minor). Some said that he was removed to the island of Naxos when his father came in search of him, and was raised there from that time onwards.

There were also numerous local traditions in which Zeus was said to have been reared  in mainland Greece (especially the Peloponnese) or Asia Minor. According to Arcadian tradition, for instance, Rhea brought him to birth on Mt Lykaion (an important centre for his cult), and three local nymphs, Neda, Theisoa and Hagno, reared him on  an area of the mountain that was known as Kretea. Neda was the nymph of the river Neda that rose on Lykaion and flowed westwards into Messenia; it was claimed that Earth had caused it to spring forth at the request of Rhea to enable her to wash the new-born Zeus. And the other two nymphs were eponyms of springs on the mountain. The Messenians claim for their part that the Kouretes had conveyed the infant Zeus to their own territory, where he had been reared by Neda and Ithome (the eponym of the Messenian mountain of that name). In reporting this Messenian tale, Pausanias remarks that it would be impossible, even if one should wish it, to number all the peoples who insisted that Zeus had been born and reared in their land.”

 - The Routledge Handbook of Greek Mythology, by Robin Hard