What is it called when two couples say for instance: Bob is with Carly and curly Sue is with Tom and the four of them have sex in the same bed and change partners, like Curly Sue is trading place with Carly and is now screwing Bob and Carly is trading places and is screwing Tom. What is that called when you switch partners? I'm so naive.
'Moral indignation is jealousy with a halo'- H.G Wells