Our closest thing to a gang bang was me watching five black guys take turns fucking my wife for six hours. It began around midnight and ended around 6am when the guys were finished and went to breakfast. They invited us to join them for breakfast but Kate was exhausted and I had a lot of clean-up to do. They came in her mouth, on her tits, and many times in her pussy.
I have watched my wife with two, three, or four guys several times. I mostly just watch and stroke my cock then clean her up when they are finished with her. Sometimes when it is just two guys, I will clean her up between fucks.