The person denying the accusation is making a counter-accusation that the other person is making a false rape accusation. (This didn’t happen in the Kavanaugh case, though, because he said the accuser was mistaken. Nobody really accused her of being a liar.)
The woman has the benefit of “rape shield” laws that prevent people from prying into her sexuality, to find out if she’s a slut. The man has no such benefit; people will ask him about his sexual behavior. That’s kinda fucked up.
As a matter of fact, during both my court case for threatening the President, and during my CPS case, I had to disclose a lot of stuff about my sexuality, even though I didn’t have a sex offense on my record. They would never require that of a woman (e.g. August), even though she was involved in prostitution.