1. Act like a bitch, and shut the hell up, calm down, and do whatever the fuck you are told to do.
2. Used in Prison Slang "bitch up" means to bend over, spread legs, and take the position a female regularly would, in order to proceed in intercourse.
1.I once told my dad to "Bitch up", and he bitch slapped me across the face.
2.One inmate said to antoher, "Leroy, you better bitch-up, you gonna have some lovin' like you aint never had, and sho' 'nough better not fight it, Or i will kick yo' ass."