He then shifts his weight slightly forward so that the shaft of his erection is producing firm pressure and friction on her clitoris as he moves.
And since the tendons of the legs pivot deep in the pelvic cavity, moving them around will subtly alter the below-the-belt sensations for you both.
Your legs should be close together inside hers.
Or, you might try humping and grinding your clitoris against your partners leg while they pull your hair or massage your breasts.
Lie down in missionary with your partner on their knees, leaning back onto their heels.
Ballet Dancer Emily Schiff-Slater Do It: Standing on one foot, face your partner and wrap your other leg around their waist while they help support you.