To motorboat down under... what more do I have to say?

When you think up something brilliantly righteous while baked.

The act of separating a pair of vaginal lips with a boomerang and blowing the inside like a motorboat.

When you're performing cunnilingus on a woman and you blow into pussy lips like a trumpet, causing the lips to flap

1. Motorboating but down under and bit to the rear.

2. The act of someone oscillating their face back and forth while pressed against your gooch, while making 'brrrrrrr' sounds.

3. Motorboating for your gooch.

When you put your face between her cheeks and motorboat her butthole while shaking your head violently.