This describes a wrestling/fighting move whose etiology stems from school fights. It is where a person gets their opponent on the ground on their back and sits on top of their chest or stomach. The arms can be held down or the knees presses on the loser's shoulders.
The manuever is common between two women who get into a fight. Often the winner will emerge victorious by sitting on top of the defeated loser. It is also used in mixed wrestling where the woman pins the man by sitting on him.
Did you see Marla whip Sarah? She sat on her stomach for a schoolgirl pin and wouldn't let her up!
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.