Im talking about the division of whore and wife the most men divide women mentally

Im a man but I personally never felt that. The closest I got to it was caring if my girlfriend was at least as sexually open with me as to any other man in the past. I think its "fair" once if im going exclusive with her I want a girl how really has a good sexual chemistry with me

But most of the discussion around it is clearly sick. It focus on body coint like a expiring date to women. Whats happening here???

Can you explain this phenomenon