Male to male = The joke has passed and I'm buggered if I'm going to look like an idiot explaining it to you, the idiot who did not hear or understand my lightning quick gag.
Female to male = The underhanded stab at the situation has passed and I'm buggered if I'm going to tell you what evil statement I made because I don't have to, you'll be just as mad at me if don't reveal the rotten thing I just said about the whole ordeal.