Intense, inexplicable jealousy of people you aren't friends with who share, or are potentially trying to steal, your friends. Especially prevalent in boys with groups of female friends that other, rival boys then befriend. Frienvy is accompanied by possessiveness, bitterness, douchebaggery, and insistence that the OTHER guys are "sleazy" and just want to "get in" with the girls so they can "bang the living shit" out of them. Also, guys suffering from frienvy will deny the fact at all costs.
Guy 1: Dude, did you see that shaggy-haired lacrosse player mackin on all our friends? Problem sets aren't what he wants.
Guy 2: Yo, chill, man. Sounds like you're suffering from a pretty serious case of frienvy.
Guy 1: Fuck no! Look at him! He's such a douchebag! This is legit!