I think, from what you’re saying, he was biding his time. If I had a platonic male friend, I personally wouldn’t start talking sex with them unless it came up as a general topic, or I developed feelings for them, but I accept that’s probably just me, and others may talk about sex more freely without having a hidden agenda.
I also don’t think it was your fault the night got ruined (I’ve been blamed for this before, wasn’t really my fault either). You didn’t ask that woman to do what she did to you, he really should realise that (unless he was already too drunk to think straight by then? Or maybe he would have blamed you anyway).