A person who you think is one of your friends until he sells out to his bitch of a woman.
Common characteristics are:
telling the guys that he will go out with you, only to decide to stay at home with the Mrs. and play cards, and then not get laid.
driving 50 miles out of the way to pick up candy for the Mrs. because she told you to do so.
Having season hockey tickets with your buddies but then cancelling, only to then buy other tickets to the same games to sit away from your friends with your bitch girlfriend.
Selling out for the sake of getting some, and then not even getting it!
Jayms forgot all about "Bro's before Ho's" and so now his name will live in infamy under the definition of a sellout to his friends.