In a mature story, a woman used a unique submission move to make a man tap out. While he was on his back she layed herself ontop of him, facing him. She wrapp her arms around his head and pressed his face into her chest, smothering him. At the same time she wrapped her thighs around his member and squeezed. The combination of being unable to breath and the extreme pressure on his member, cause him to tap out. I've never heard of such a submission move before.