To the younger folks out there: if you see something like this occur as a third party (you're neither the groper nor the gropee, neither the misogynist nor the victim), you need to not politely ignore it but to step in and correct the asshole, as firmly as necessary.

Whether it's groping or just verbal putdowns of some sort, you should step forward and add yourself to the situation, making it clear that the behavior you witnessed is not acceptable to you.

Otherwise, you're part of the problem too.