It's so surreal, insane and triggering, that it can only be a trolling function.
What woman would say yes to this request? Not even the most trans friendly trans maiden would say "sure buddy/buddyess, c'mon join me, let's piss away with trans abandon!"
And this perp knows this. Thus he has a bunch of women who are constant victims and targets in his misogynist tirade against the female sex class. And his friends are in on it, or more likely if some are female are tested internally but maintain the face of the mob...groups of bullies always have reluctant members.
It's just the thrill of the troll. And the more you can threaten and troll women in public, the more thrilling it is.
Ditto the erection-bearing, latex-wearing lay-dee at that lesbian speed dating event. Different individual perp, different individual victims...same warp, same effect.
My GF some years back came across a flasher walking home across the park. "Touch it, and I'll go away" was the demand. She didn't react the way he wanted. Back then, this was unacceptable. My point is that this incident in the pub is not different in any meaningful way. Yet had the police got involved, my GFs flasher would have been dealt with, this pub perp would have got kind words and a pat on the back.
Different eras, different attitudes.