It was almost 5:30 and Stephan had not come out yet. I walked down the hallway and I heard muffled groans. I took a chance and opened the door just a ...ew inches and I could tell it was Mary. I opened the door just a little further and saw that Stephan had my wife bent over the table. He was plowing into her very hard and Mary was face down into a pillow, trying to muffle her groans. My view was from the back and I watched Stephan's ass cheeks tightening up every time he rammed into Mary. I saw. “Sweetie, it’s ok. No need to be embarrassed. We don’t mind you watching us. Did it turn you on?” “Well, erm…” Nathalie was gobsmacked. “Do you want to see us live”, Frank said unbuttoning his shirt. “yeah sweetie, we’ll give you a good show” Katie said stroking Nathalie’s neck. “Come with us” Katie said grabbing Nathalie’s hand and pulling her up. Dazed Nathalie got up, not thinking straight. The blanket fell to the floor and Nathalie suddenly stood in the middle of the living room. Physics tells us that air resistance and the spin of the baseball have an effect on the baseball’s trajectory. It’s called the Magnus effect, and it’s the reason that a pitcher can throw sinkers, sliders, and curveballs. It’s the same with batting. If you use the chopping method to hit the ball further, you have to be perfect every time. If you don’t hit it right, you clip it. It’s on the ground, or it’s a foul out, or it’s a backspun fly ball that goes nowhere.“The opposite is topspin. That. Pulling up her dress with his other hand as she slid her leg further up his, inviting his exploration. Peter slid his hand further up her inner thigh, upon reaching its destination he found no panties covering what was by now a very wet sticky pussy. As he slid a finger inside she groaned with pleasure and her grip on his hard mass intensified. He added another finger to the wet wanton tunnel, sliding them in and out gently.The kissing became even more lustful as their tongues became frenzied.