Clapturbate

When you swing your penis up and down so it goes between your legs. When it goes between your legs it will reach between your ass cheeks and your ass cheeks will clench on your penis and you will pull it out rubbing along the taint eventually leading to ejaculation. Right before your penis gets clenched between your ass cheeks it makes a huge clap noise upon impact so you are essentially clapping your cheeks. This works best with shit stains in your ass cheeks, they work as a lubricant.

Making air humping motions to flap your penis up and down so it goes beside your legs and into your ass crack. When it goes between your ass crack you clench on your cheeks so it has to squeeze through them to get out. This causes your penis to rub on the inside of the ass crack and part of the taint eventually making you ejaculate. The noise you get right when the dick hits between the ass crack before you clench them is a huge clap noise so you are essentially clapping your own cheeks.