Somebody who pretends to be cool, but actually is an idiot. Male form of teenybopper. From Bulgarian slang. In Bulgaria, the assers are currently on a gangsta rap wave.
Heah, Bobo's pretending he's a big asser just cuz' he listens to 50 cent and other shit of the sort.
Non-Single Girl 1: OMG did you see those abs?
Non-Single Girl 2: I know don't you wish **boyfriend** has abs like that
Non-Single Girl 1: Hell yeah, gimme a piece o' that.