The act of being infuriatingly like Chuck Bass. Usually incorperates sleaziness, womanizing, boozing, smarminess, snarkiness, and being self centered.
"Damn that Mother Chucker, he's totally right." In this instance the subject of the Mother Chucker Conundrum rightfully (if not more self centered) assumed that the object of his affections was using another man to make him jealous. Being completey egocentric and self centered, he guessed this being full of himself, but also knowing that not only he, but said object of his affection was completely in love with him.
Blair (after seeing Chuck with an older, attractive "friend"): Damn that motherchucker!
Serena: I was expecting that.
A stupid idiot that is usually fat,gross and has no life. It's another word for mother fucker that you can say in school and not get in trouble.
Get out of here mother chucker!!