I'm so sick of their shitty rhetoric. You are men, we all know you are men, every doctor can tell you are men, and in the vast majority of cases everyone can tell you are men even without seeing your genitals. Yes we can biologically define what a man is, yes we can find biological traits that all men have, but frankly you obviously just try to scramble our brains with this shit because everyone know you are men. Including you.
It's like some man would put on wings made of felt or something and says he is a bird or a fly, and when people tell him he is a human he would argue "what is human anyway, find one biological trait that all humans have". Not all humans have legs, not all humans have arms, not all humans hear or see, some people are born without a face or heart or stomach (all true stories). So you can't possibly definite a human, right?
Of course we can. But it isn't needed anyway, because you are obviously a human, and this is all ridiculous.