Kacck
Using your sausage to make a circle while you're letting your sperm fly, no help from your hands or your brain.
His sausage was going in circles like it had a life of its own while he was blasting his jizz.
She was cumming so hard, her sausage was doing the cha-cha without asking.
I didn't touch my dick, but it was doing the twist while I was sploshing my load all over the wall.