I've always wanted to some day try this. It's where couples switch the persons, like they would change women or something. It's crazy and weird but it might be fun. The only reason it would cause problems for me is if he was better then me, then she might tempt to do it again without permission. It could cause cheating and breaking up in the end. But, if you know for a fact that your better at sex then him, then you should do it, cause your wife or gf would want you back immediatly, then his wife/gf would want you as well. haha