The behavior set that you are mindlessly defending ( he only touched a grabbed a girl's ass, while drunk, we've all done it) is the exact mindset that the #metoo movement is trying to bring to light. This is not a game of absolutes, it isn't a binary decision of rape/not rape. Harassment is harassment and no one can tell you how it affects the person it is done to, except for that person themselves. The type of behavior I'm seeing on this forum is what enables this mindset to continue to flourish. You don't defend "light harassment". You apologize for the behavior and try to change. You adapt to the changing times, and yes, grabbing a girl while drunk is considered harassment. Talking to a woman in a sexual way when she doesn't consent is harassment. Leering at a woman is harassment. Calling a woman a bitch because she turned you down or doesn't want to engage in sexual activity is harassment. The list goes on...
I've been here 10 years, but seeing all the shit that has happened here in the last few months, this is no longer a community I want to associate with. Good luck to you all and I hope as you grow and mature you learn to see things with other's frames of reference, especially those who are different from yourself.