The body swap spell was very good, but the catch was that you were unable to orgasm. If one of the pair said the magic word I would make the change permanent, but of course they would be stuck. Richard and Anne decided to experience what sex would like from each other's perspective, it would make them better lovers they reasoned.
As Anne started to pound Richard, their unreachable orgasms started to build up, and build up, and build up. They could not stop because it was incredible; but they just couldn't reach a climax. Finally Anne could stand it no longer, she yelled the magic phrase and shot her load deep into Richard. Richard felt Anne's penis throb and twitch inside his body, he orgasmed with wave upon wave of pleasure. They stopped, both gasping for breath, then they realised what they had done.