The dream is so vivid, you feel your body, grinding against the covers, you can feel the warm wet patch of drool on your pillow that your cheek is pressed against, your pussy feels so alive and sensitive, your hand travels, purely powered by muscle memory, towards your clit.
As you lift your body to rub yourself, the realisation dawns, this is not a dream, you're weighted down, he's fucking you. Instead of rubbing your clit, you reach down, grab his balls, so heavy, sweaty, as they slap against you. Is it because he's been pounding away, is it because this feels so deliciously dirty? Whatever it is, you're whimpering, bucking, "fuck me...please" you beg him, grabbing a tit with your spare hand, orgasming instantly, crying now, "cum in me!".