When two (or more) parties post up ambiguously malicious Facebook status' in an attempt to hurt/anger/piss off the other party/parties involved. Facebook Status Jabs are usually indirect and contain subliminal messages meant to piss the sh*t out of a specific someone.
John Milner is happy that he FINALLY found a girl whose
cup size is nowhere near an A!
*Claire (John's ex-girlfriend) logs on to Facebook and reads John's status*
Claire is hurt/pissed/angry by her ex's Facebook Status Jab at her 'mosquito bites' so she retaliates...via a Facebook Status Jab (of course) lol
Claire Johnson is glad she FINALLY found someone who doesn't live at his momma's house :)
...ah, Facebook Jabs - don't you just love 'em !