A karate-chop hand motion delivered to a guy's crotch. Was originally invented to be done with an actual tomahawk, but it was then decided that the receiver might not want to be sterile for the rest of his life. If you try it, ladies, just make sure the guy is into being dominated...

the thing that you don’t have when you’re phones percentage is over 20

While having anal intercourse "doggy style", just as the "giver" is about to ejaculate, a forceful blow is delivered to the "taker's" throat region in a semi-circular, undercut, "tomahawk chop" like fashion, in order to illicit the involuntary desired effect of the "taker's" rectum to tighten, or pucker, so that the "giver" is able to withdraw his penis relatively fecal matter free.

The act of folding your right fist to your right armpit and sliding your elbow into the vagina and, possibly up to your wrist, ram in and out in a chopping motion.