saddle boating

The placement of one's face, specifically the mouth, into the area between a woman's buttocks, followed by a rapid shaking of the face in a side-to-side motion accompanied by expelling a large amount of air. The resulting sound that is created sounds similar to an outboard boat motor.

Frank, looking for a change, and because his chick has a sweet badonkadonk, engaged in saddle boating much to his girlfriend's delight.