There are places and times that just feel right. You have to make the decision yourself. First time my first wife and I had enjoyed a 3some with her gf. I felt like a King. It was so much fun. When she asked about a second guy, how could I say no? Of course that night alcohol was flowing, and we both satisfied my wife. Later I felt a sucking on my cock. It was him! My wife laid across me, and asked if it felt good. I said yes. I just let it happen, and I felt the urge to suck him too. I liked it. Second wife and I were a bit in the swinging life style ( she loved eating pussy and ass) and that was a great time too. You just have to let it flow and whatever feels good, do it.