An exclamation made when one insults their friends concerning something sexual in nature, usually to do with how sluttly/easy they are to get into bed. Derived from the C-Cup size of a girl's "Jugs", or breasts. Due to the fact that everyone loves a girl with big boobs and the easy nature of said girls with C-Cups or bigger, one says C'Jugs (pronounced ka-jugs) to add to the insult just made for more emphasis.
Girl A: That test was so easy.
Girl B: Yeah, it was, like you. C'Jugs!
A: I would love a hot dog to put in my mouth right now.
B: That's nothing new for you, you're always putting meat in your mouth. C'Jugs!