On the plane on the way to be with me!
When I was stationed overseas, I arranged for my wife to come join me, which meant a VERY long ride in a jet. When she got there, we went straight to our apartment and had sex. When we were done, I admitted to her that I had been unfaithful one time since I got there; she didn't get upset like I thought she would. Instead, she had something to tell me: "I did something, too." It seems that on the way over, she was seated next to a friendly Army sergeant who made her feel more secure. That night, when the plane was dark and quiet, he snuggled with her and asked for a blowjob--and she did it! She sucked his dick and swallowed his cum, then she spread the blanket over her lap and he fingered her pussy to orgasm. They snuggled and got a nap, then said goodbye when they finally arrived at the airport. My wife and I more or less called it even and let it go. A month later, we had a family day party at my unit. Suddenly, my wife turned red in the face; "That's him!" The guy she sucked on the plane was in my unit and I knew him! I had no intent to start any trouble, and I wasn't angry, but I couldn't pass up a chance like that. I called him over and said, "My wife tells me you and she rode next to each other on the way over here." He turned a little red himself and said hello to her. I left them alone while I got us some snacks--just a few minutes. Later, my wife told me that as soon as I was out of range, he asked "Does he know?" "Yeah, but it's okay," she answered, "he was no angel, either!" He was extra friendly to me after that.