They both, as adults, decided to get blind drunk in the first place. What happens after that point is to some degree irrelevant though Michelle is probably extremely lucky that Peter (assuming it was him and not his doppleganger) didn't break or tear anything off her.
Which raises the point of whether or not you're legally obliged to inform a potential fuck budy if you've got non-obvious superhuman qualities, especially something like superstrength or massconversion.