Mindy pulls Isabel's panties down

(this chapter originally by "shyexposure")

As the class got into position, Isabel smiled to herself as she knew she could then pull her pants up and cover herself. Finally she'd get her modesty back in tact with no one the wiser. Little did she know that Mindy knew everything, having been the unseen help in her predicament, and she wasn't about to miss any golden opportunity.

As the instructor told them to get into position, she reiterated that they needed to do so slowly. This was to maximize the burn in the girls' muscles, but also to help them relax. Mindy smiled at this, for here was the golden chance she had been waiting for to happen. And she was going to snag it for all she was worth. As Isabel shifted position, Mindy reached forward and gripped the sides of Isabel's panties, then slowly started to lower them, looking around to make sure she wasn't found out.

Isabel panicked internally. Not only were her white panties on full display to anyone, but even those she could feel descending! This could not be happening to her, not here! Suddenly rigid in her spot due to her hyperactive nerves, Isabel did nothing as first the top crack of her butt was exposed, then more! What was happening?! Did she put on clothes larger than her body without meaning to, or had they stretched in the wash? She couldn't figure it out.

As she remained in quiet panic mode, Mindy couldn't help smiling. She almost had it--there! With a victorious gleam in her eyes, she managed to drop Isabel's panties to her ankles along with her pants. From her place behind the girl, Mindy had a perfect view, both at Isabel's ass, and between. What she saw made her smile grow, for those soft pussy lips were pretty pink, and engorged, despite what their owner might think. Qucikly so as not to be caught, Mindy resumed her pose, just as Isabel looked around frantically.

It was then...