v. int. Similar to motorboard; however, the act of pushing one's face in between two barely-there breasts, and rocking one's head side to side very rapidly while making a vigorous, lip-vibrating "brrr" sound.
You can motorboat Deb because her breasts are triple D's. You can only motorboard Linda because she's so flat chested.
by linda jo March 22, 2011
When you try to motorboat a girl who is flat chested.
Deb is too flat chested to motorboat, I'll just have to motorboard.
by lindajo March 18, 2011