the act of motor boating but using a woman's ass cheeks in place of a woman's breasts
Bob really is an ass guy, so he decided on motor butting Nancy
by phildothegreat October 18, 2013
The act of perform a motorboat, but on someone's anus.
We were about to start some rusty trombone, but it wasn't hard, so I turned to doing some motorbutting.
by scumbeater November 15, 2013