This hyphonated phrase is the contraction of "Bad Boys Know you suck laugh out loud" It is used to insult badies and n00bs by old fags. It may also be a contractions of
"Bitching Bad Kid you suck laugh out loud"
As to if the lol is a predicate object, as in telling you to suck a lol, or just an attached phrase, we'll never know.
Novice - "My crit chance sucks and I can't get moar armor"
Old WoW Fag - "BBKusuklol" *logs*
Novice - "Fuck..."