Imitation of reverse cowgirl. An indicator that a chick knows what's up.
A gesture often done in night
club environments by
girls to entice men and to simulate what will ensue in
bed if you got with them.
"Check her out, she's twerkin'
dat ass at Josh. She knows what's up"
"Oh
man, you should have seen how she was
grinding against his cock after that"
"We know that he's obviously getting some"