A sexual act when having a woman with a huge booty ride you, and you put a pair of stereo speakers on both sides of her butt cheeks. The bass needs to be turned way up, and you need to play a song with a lot of bass hits. Her booty vibrates so much that you barely even need to move your hips.
Man, that girl was so freaky last night! She even put on Blackeyed Peas and laid the Boom Boom Pow down on me!