Never heard that. I've heard stupid b!tch (when a woman does something stupid) and stupid c#nt (when a woman does something stupid that she should have known better than to do, and probably did, but did it anyway). P***y has a pretty fixed meaning in slang to mean someone weak/whiny, so I'm surprised your friend uses it in a non-standard way.
The way he used it was to describe women who think with their private parts.
Voting for someone because you think he’s cute, or because she’s female would fall into this category.
He saw women like that as very shallow and good for only one thing....