Knee fuck

From Voyeurweb's Wiki

Knee fuck is a rare sex position between males and mostly females. Both partners lie flat on their backs beside each other. She bends her knee which is at his side in a way that it forms a crease and squeezes the shaft of his penis between her lower thigh and upper calf. Due to the applied pressure his penis will start to further erect, especially the head of his penis. She now starts moving her hand up and down the head of his penis while changing the applied pressure of her knee.