this guy cant have shit! (reupload cause I forgot to give this guy leg hair... i HAD to fix it...)

I think there is A LOT in the fact that Crowley chooses to kiss Aziraphale.

Gabriel and Beelzebub have chosen each other, yet the show is very careful in not having them kiss or even hug romantically; they are Superior Beings, not humans, so they don't conform to humans' way of performing, showing, or possibly even feeling love. If they were humans, I'm sure they would have happily kissed before disappearing into their happy ever after, because that's what (most) humans want to do in such circumstances, and also because it's a fast and sure way to clarify the feelings to the audience.

This is in contrast with the kiss Crowley chooses to give -a very rushed, passionate, not though through, human kiss. He had already talked about his feeling (as Nina suggested), he had already made a confession, no one at that point was in doubt about where he stands for Aziraphale. So why the kiss? It wasn't necessary to clarify his feelings...or was it? I think is was necessary to further clarify them. To me Crowley is not saying just "I love you" with that kiss, he is also saying "I love you in a human way, I love us not the Angels we could be Up There, I love us here on Earth".

He does not want to be back in Heaven, not even with Aziraphale; he's been there, he's been there in a very high rank, he knows that it is not a nice place. He wants to stay on Earth with Aziraphale and that's what he's trying to tell him by choosing to show love in a human way.