flappy bob 

a flappy penis that falls out of your underwear when you run

"Yo ma nigga i b runnin dis mornin and my flappy bob hit me in da face!"

flappy bob by FlappiestBob July 14, 2007

floppy bob 

When your balls slap against a girl while in the doggystyle position

I was doing her doggy style last night, started going too fast and gave her the floppy bob!

floppy bob by Bob the flopper November 15, 2017

floppy bobby

big massive sweaty dump that you take when talkin to somebody called danny !!!!!

antony garnett has just done a floppy bobby in the lav

floppy bobby by keith lemon fdge January 16, 2009