Sexual fetish involving Mary-Kate and Ashley, back to back before you; you on your knees, alternating thrusts of your love shaft into their V-units, springing back and forth between the two until euphoria ensues. See California Mud Hopper. Dirty Nail optional.
It wasn't the Olsen twins, but I did have a psuedo-Full house hopper last night with Lisa and her mom. My hips were like a sewing machine doing a zig zag stitch back and forth over that slippery cloth.