A momentary increase level of excitement between your legs
OMG, did you see him/her...what a flash in the pants....
by SOB13 September 25, 2009
1 more definition
a momentary burst of sexual arousal (a pun on flash in the pan)
I had a flash in the pants from thinking about the night before, but realized I can't let it interrupt my work.
by The Return of Light Joker November 01, 2011