When a girl wrestles another girl down onto her back and then proceeds to sit on top of her chest, breasts or neck while straddling her knees on either side.
This move is used in unorthodox female wrestling, like erotica or unofficial wrestling competition. It is very hard to escape from, especially if the person initiating the move is heavier than the girl underneath and has good balance. It is also very nice to watch.
Girl sits on another girl's chest. Yay schoolgirl pin.