I've been on the receiving end of persistent 'grab ass'.
I had to tell the person that, while I wasn't offended, if I did that to someone, I would be (rightfully) sacked.
The person groping me was a man.
I've heard horrible stories from my daughters and my wife about similar instances.
The significant difference was that, for me, if I really objected, I could follow that up with physically defending myself (it was one individual).
For my daughters and wife; not only couldn't they have physically fended off a man, it was often a group.
I have known two men who were raped. By groups of men.
There is a common theme here, and it is gender.
I've been on the receiving end of lewd or suggestive comments from women (drunk and sober). But that is all; comments. And when I rebuffed the advances? Either laughter, or embarrassed retreat (by all parties).
Men?
When my step-daughter refused to get in a car with some men, they screamed insults at her and tried to drag her into the car.
Three times I've had to intervene when a woman has been fleeing violence, or been at the receiving end of violence.
The common reaction of some (significant proportion) men, when rebuffed (sexually or socially), is to get physical. Men do it to men. And they do it women.