Mark tries to see more

Lauren looked up from her prone position as Mark moved over her. Mark, whom she'd taunted and teased, and lured on a long line for years. She fantasized of him over her, but it had always been in a private, erotic fantasy. Not when she was laying half naked on the floor in front of her sister and rival!

Mark moved into a crouch, placing a hand over each of her bare feet. Lauren had her knees slammed together. She hoped, prayed that would obscure her most sensitive area, but with her ankles spread as they were, she had no guarantees.

"What are you waiting for?" Vanessa asked. "Five more sit ups, right now!"

Lauren closed her eyes. She couldn't look up at Mark while she did this. She bit her lip. Then, struggling, she pulled herself into a crunch. She had her eyes closed, but she could feel her stomach rolling and folding in the most unflattering way imaginable, and knew Mark was seeing every detail of her shockingly thick middle.

Mark, for his part, barely noticed. He was trying to get a good look at what was hidden between Lauren's knocked knees. Unfortunately for Mark, Lauren was doing a very good job keeping her knees locked tight. He saw some glimpses, but whit Britney watching he couldn't move to get the up-close angle he wanted. He found this frustrating, though his arousal only grew.

Finally, after what felt like an eternity for Lauren, she did five more sit-ups. She fell back on her back, throwing her hands over her crotch. A bit disappointed, and struggling to walk with his massive erection, Mark rose to his feet. Vanessa grabbed Lauren by the shoulder and yanked her up. Lauren's whole body was coated from sweat, her breathing heavy from this brief workout.