look up any word, like dirty sanchez:
 
1.
1. When your penis slips out of its holster, its barn, i.e, your pants.

2. Also may refer to unnatural through the clothes protruding during mid hug. Context will be your guide.
Looks like you got yourself an accidental slippity doo!

OH MY GOD THAT OLD MAN JUST HAD A SLIPPITY DOO AND ITS JUST HANGING THERE.
by mydogspenisisbiggerthanyours April 14, 2011