On Cindy's ass.

Before you realize what has happened, your wife crawls down alongside of you and Cindy, while you continue to pump Cindy from behind. Diane places her right hand on the small of Cindy's back as it moves back and forth from the motion of you fucking her. Cindy rests forward on her elbows and turns to watch you and Diane. Diane then places her left hand on your shoulder and begins to kiss you passionately. You notice her move her right hand across Cindy's ass until it reaches your cock, and then she gently pushes you away from Cindy and your prick pops out of her. Immediately your wife has her fist around your cock and begins to pump it as Cindy still moves in rhythm as though being fucked still.

Diane expertly jacks you off and you come gushing over Cindy's back and ass.

You collapse back into a sitting position as your wife lets go of your prick and massages your come into Cindy's back and with her right hand, and pushes some come with her left hand under her bikini bottoms. She moves her fingers down the crack of Cindy's ass until she plays with her clit. Diane extends her middle finger into Cindy and again Cindy arches her back while pushing her pussy into Diane's fingers. Diane then lays on her back and scoots her face under Cindy's crotch. She pushes the bikini bottoms aside and replaces her finger with her tongue. Her finger moves up under the bottoms until you can see she is now fingering Cindy's rectum.