My wife and I enjoyed regular (a couple of times per month) threesomes with her married co-worker. He loved for me to fuck her first, to get her ready for him. The three of us agreed, cum is the best lubricant. He was highly aroused watching me quickly fuck her so it all worked out well. I prefer "Seconds" given a choice, but because I don't last long (1 - 5 minutes) after she's had sex with him, we found it was better for me to go first, then leave the room and spend the night elsewhere in the house.