Tribbing on LetMeJizz
Two women lock their legs together and grind pussy against pussy until the friction does the work, no toys and no cock anywhere in frame. Scenes usually open with kissing and fingering before one climbs on top and starts riding her partner's thigh, then they scissor so both clits drag against each other. The rhythm builds as they pin hips and chase the angle that hits hardest, faces going tight while they grind faster. What sells it is the mutual buildup, both of them working toward the same finish off the same contact.
172 tribbing videos here, all HD and all free. New ones go up daily, so check back if you don't find your scene first time around.