When a mans side bitch or side hoe starts having an attitude towards the man because she is mad that she doesn't get the benefits of getting what she would get if she was the girlfriend.
"So we goin' anywhere to eat tonight?"
"Nah."
"What am I gonna eat then?!"
"My dick."
"I wanna go out! I wanna go somewhere with you! I hate having to be a secret!!"
"Bitch shut the fuck up with that sidebitchyness! You're the side bitch! We're supposed to be a secret, OK?! I can replace you in a heartbeat."
While sometimes mistaken as a simple prefix added to the common epithet 'bitch,' 'slumbitch' is actually a slurred form of 'son of a bitch', but useful for both genders. Instead of an insult, however, it is most useful as an interjection when events do not conspire to your fortune.