The "problem" was a ruse to lure Mackenzie into a trap.

(chapter originally by Bluefish at writing.com)

Mackenzie was confused - the girl looked fine. Now that she was in the room, she could see that the other girl - who had straight blonde hair and was wearing a red bikini - didn't look upset or even uncomfortable. In fact, as the door swung shut behind Mackenzie, the blonde actually had a smug smirk on her face. "What do you need help with, exactly?" Mackenzie asked.

The girl shrugged. "To tell you the truth, nothing. I just needed a way to lure you in here."

"Wh-" was all Mackenzie had time to say before hands grabbed her from behind. She let out a shriek - someone, several someones, had been hiding on either side of the door when she came in, and now wrestled her down to lie on her stomach on one of the benches. Twisting her head around as she fought, she saw that she was being pinned down by several grinning college-age girls. The blonde was watching with obvious satisfaction.

"What is this? Who are you?" Mackenzie demanded, struggling. "Let go of me, I'm the lifeguard!"

The blonde walked over to squat beside Mackenzie, looking her right in the face. "Hi, Mackenzie!" She beamed. "Recognize me?"

Mackenzie frowned, nonplussed. "Nooooo...should I?"

"Probably. I'm Sarah - from your trig class?" She was still smiling, but now two spots of color were reddening her cheeks. "Last year, you and your sorority friends thought it would be funny to lock me outside wearing nothing but my panties."

"I still don't...oh wait, I remember now! You were wearing a pink thong. And you had to run all the way home like that! Everybody saw you, pictures got on the Internet and everything." Mackenzie giggled at the memory, and immediately regretted it when Sarah's smile vanished.

"Yeah, well," continued Sarah, blushing harder now as her past humiliation was revisited. "I remember you thought that was awfully funny then too. I wonder...is it still funny when it happens to you?"

The bottom dropped out of Mackenzie's stomach. She barely had time to get out a "noooo!" before she felt hands yanking the straps of her swimsuit off her shoulders. She was pulled upright and her arms were worked out of the straps despite her protests. Sarah, looking Mackenzie dead in the eye, reached out a hand to grip the front of her swimsuit, wink, and say "Payback time."

Then she yanked down with both hands, pulling Mackenzie's swimsuit all the way down to her thighs. Mackenzie screamed again as she felt a shock of cold air over her entire now-naked body, her round breasts and mostly-shaven crotch totally exposed. Sarah took advantage of her shock to pull her swimsuit completely off. Mackenzie was now fully nude from head to toe.

She tried to cover herself, but her arms were still being held by Sarah's friends, and she wound up doing nothing but making her bare breasts jiggle as she struggled. "Let me go! This isn't funny!"

"You sure thought it was funny when you did it to me! This is just a little cosmic balancing of the scales." Sarah folded her arms and surveyed Mackenzie with satisfaction. "Question is...now what?"