A male displaying percieved feminine characteristics through actions which cause his peers to think less of him.Being a big girls blouse is much worse than being just a girls blouse, thus it's highly insulting nature.Also used to force a man to do something they fear through peer pressure.

Psychotic:I don't want to to go sky diving while having sex with you.
MANUS: Don't be such a big girls blouse.get in the plane and bring the condoms. dear.
Psychotic:Fine...