Why do people feel the need to make their sex lives public?

[Kiki]

In my experience it is younger men that brag the most about their exploits. I was actually prude-shamed, for telling some of my husband's friends (many years ago) that they should be respectful of their girlfriends, and not go around telling us all details that we don't need to know.

I know that with these fellows, it was a case of posturing or making themselves sound like macho dudes who get into their girlfriend's pants on a regular basis. Some of the girlfriends were okay with it (or claimed to be be okay with it) and some quietly told me they felt humiliated.