"I can't exercise bottomless!!!"

"I can't exercise like this!" Lauren exclaimed, shocked at the very notion. Of course she wasn't exercising with her bare ass and crotch hanging out!

"Why not?" Britney asked. "It's just the four of us. We're perfectly safe in your apartment.

"Besides, I'm not just giving you more pants to split." Vanessa pointed out.

"B... but Mark's here!" Lauren exclaimed desperately. She didn't want to point out her biggest source of shame to her tormentors, but she couldn't help it.

"So? Mark, you don't mind do you?" Vanessa winked at Mark. SHE had noticed his raging hard on at the scene.

"Not at all!" Mark said enthusiastically. Despite how much he was enjoying seeing his girlfriend and Vanessa jump around in skimpy outfits, the thought of seeing Lauren's naked bare butt while she worked out had him near the bursting point.

"There, it's decided." Vanessa said. "You're not getting out of this workout lazybones." She laughed, pretending THAT was the reason Lauren was trying to avoid this.

"Now, back to the workout!" She emphasized this with a ringing slap to Lauren's backside.