Someone who is smart and knowledgeable, but when around some people they become idiotic and stupid.
Dude was talkin' legit till Kev came in. Total intellidumb moment.
A guy shit talking until a sexy girl is near. Then he pretends to be mature and respectable.
I was talking to a guy at a bar about the last time we got hit in the nuts, but he went full pussy pleaser when the hot blond sat near us.