A variation of the bump and grind which results in accidental or "accidental" penetration...aka sex on a dance floor.
Joe: "So dude, how was the party last night?"
Dan: "Man, it was awesome, me and Kelly were grinding all night and then....we started speedbumping."
Joe: "No way man! Nice!"
Dan: "Man, it was awesome, me and Kelly were grinding all night and then....we started speedbumping."
Joe: "No way man! Nice!"
by Yeskimo August 20, 2009