I guess it all started soon after our first baby was born . Lisa had gained weight during her pregnancy and her body was out of shape. We signed up to a health club and both of us began to work out. I was into upper body things because my belly was getting a little thick from married life and the regular meals now. Lisa asked for and recieved a private tutor and he was a very nice black guy in fantastic shape. I would watch from a distance as he took her through her pases and they would laugh and talk together as she worked out. Sometimes I would stop whatever I was doing and watch her and Jim they seamed to like each other and Lisa was firming up nicely. At first I was a little jealous at her open and friendly almost bold friendship. Before we married she admitted to having sex with a black guy at Hogan High. While she was in school she admitted that several of her boyfriends had found their way into her pants and that was extreamly hot when she would admit these things to me. After Lisa was once again back to herself Jim took on another client and Lisa found that she liked the treadmill. I would work out for awhile then I would usually walk 30 mins on the treadmill beside her. Once when I came over there was a guy on either side of her and they were talking and laughing when I had to move two treadmills down from them. The two guys were both black and they ignored me talking to Lisa and Lisa was enjoying the attention and innocently flirting with them. Both of the guys were in great shape and I became very jealous at how my wife was laughing and talking to them. Christ she had on my wedding ring were they blind ? as they casually began to work sex into their conversations. I glanced over and the one next to me was probably in his late 40,s . I couldent really see the other one but my imagination was now in overdrive and my guts churned with rage but I found that I was also strangly excited and my cock was getting hard listening to my wife laugh and talk to them. After the workout Lisa came over and said she was going to the steam room and asked if I was ready but I had a hard on and I was afraid that everyone would notice so I said in a few min,s Well when I made it to the steam room hiding my erection with my towel the room was a thick fog. I could hear my wife though somewhere in the steam still talking and I recognised the voice of the guy as the same as the older guy on the treadmill. I sat there trying to see what they were doing but the steam was to thick. My imagination kicked in and I imagined that he was fondeling her B-cup breasts in the fog and my guts twisted inside of me and I wanted to drag her out of there but I was once again as hard as a rock. I escaped out before the fog thined and I made my way to the shower stalls and I jacked off cumming in a rush. That was my first introduction into my fantasy of shareing her with many black lovers . She took awhile to give in but then when she decided t go for it she was a very willing partner.