Maybe it's my scandinavian-ness but I'm actually finding the very knee-jerk reaction (which, apart from the entire drunk issue, which, yes, is stupid, and yes, is something that Peter should have to confront and consider, although I don't consider it entirely OOC) which feels very anti-sex and socially conservative, to be really skeevy.
It's actually pretty prevalent in a lot of comics, not just in this one. I don't think Peter would be the kind of person to engage in casual sex under normal circumstances... But this isn't exactly normal circumstances either.