Do you think they had sex? It was left ambiguous and we never got a definite answer.
Edit:
Well, I sent Milligan a message on his website asking him if Gambit and Mystique had sex.
He respondedI asked permission to repost his response here, and he responded,It was a while ago, but as I remember I think I intended to give the impression that off screen, so to speak, these - and a few other x-men characters - had carnal knowledge of each other. But I have a dirty mind, and I’m always trying to get the characters I write into bed with SOMEONE.Yews, but add this. As I said, it was a long time ago. But clearly if it’s not obvious in the comic whether they did or did not have sex, I wanted at least some kind of ambiguity.