Regulus can’t help but resent Sirius a little more each passing year at Hogwarts. It’s not that Sirius somehow succeeded in leaving their family, choosing his friends over his blood, and it’s not that the whole school worships his every move like some leather jacketed god. Regulus resents him because he found a new family that’s everything his isn’t; kind, loving, and unflinchingly loyal. He’ll never have that. He’ll never have someone he can trust with his secrets, no one to pass notes to during class, no one to spend the day with in Hogsmeade. He had Sirius once, but he left without a lasting glance, so why would anyone else stay?
What Regulus doesn’t know is that every night, when Sirius pulls Remus up to the astronomy tower and they watch the stars shoot across the sky, Sirius wishes for one thing. Please give me my little brother back.