Jennifer Lopez and Jimmy Fallon argue over their tight pants

Jennifer Lopez is the latest celebrity to challenge Jimmy Fallon over whose pants are tighter (hers are, it's not much of a question). As before with Will Ferrell, things escalate quickly and the campy song breaks long enough for to J.Lo to unleash a torrent of expletives and insults at Fallon. Do not brag about your tight pants if you run into Jenny on the Block.