Muscle weighs more than fat.”“Huh?”Barbara explained, “It’s the exercise. You’ve been burning up the calories, but you’ve been convertin...g some of the flab to muscle. You get thinner, but since muscle tissue has a higher density that fatty tissue, you don’t lose all the weight. You’re slimmer, but not lighter.”“Uh, okay...” Jerry looked at her in confusion.It took several minutes more of explanation for Barbara to get the idea through to him. He decided to check with the trainer at the gym the. I got to my car and could feel my cock start to twitch and the idea of fucking her and was not going to miss the chance of my fantasy.I wasn't long before we where at lisa's house I carried in her shopping and help her put it away as we chatted and waited for the kettle to boil. We were soon on the couch chatting like old times with a little flirting going on to, she laugh as I was saying how amazing she was, "your just saying that" she said "Im not trust me if I was your husband I dont think I. It was confirmed as he removed the dress covering his upper body, revealing a broad and muscular chest. He clenched her ankles tightly and continued to drive his cock deep into her.Her mind went blank and she gasped for air feeling her lungs bursting. She kicked her legs in agony, her face was a mix of pain and shame. She felt so exposed and vulnerable with her legs spread and this man thrusting in and out of her. She realized in horror that she was grunting in pleasure with each thrust. Her. . all hot and wet inside, and her breasts were so soft and hot against my chest. I wanted it to last for days.And then, before I could think about it, I was jamming my root in her as it sprayed what I knew was white slippery sperm ... all up inside her teenaged belly. I had one fleeting thought of “baby”, but all that did was make me shoot even harder.That was the first time we had sex. It was wild and unplanned and we both felt guilty as hell when it was over. I felt guilty until I went.