Person 1
Lie on your back on a sofa, bending and pressing your knees toward your face.
Person 2
Put on a strap-on.
Stand over person 1.
Put one of your feet next to the head of person 1 and the other on the armrest behind you.
Crouch over person 1 and place your hand on the back of the couch for support.
Then penetrate them.
Person 1 grabs your shin for support.