My ex and I tried swinging and, at that time, we had neighbors, Jimmy and Donna, who were also swingers.
One day I came home from work, looked in the living room, and my ex was laying across the couch, sucking Jimmy from the side, She didn't see me, her head was bobbing up and down in Jimmy's lap. But, Jimmy saw me. He just pointed to her head and shrugged his shoulders. I moved on to the kitchen as silently as I could.
What you never get used to is when you hear the guy loudly grunt and holler out of nowhere, breaking the silence