"i gotta take a piss...tap tap"
Also used as a reply to confirm the fuckability of the girl.
Warning: Not to be used when wives, girlfriends and mothers-in-law are within hearing distance.
Guy #1: Tap tap
*Guy #2 immediately turns head to see who walked through the door*
Guy #2: Tap tap
"Then, a tap tap jumped out of the bushes and stole my wallet."