Lenny trudged down the crowded hallway to gym class lugging his knapsack full of textbooks and a half-finished term paper that was due yesterday.

"Hey dude!" his friend, Brad, called as he came up behind Lenny. "What do you suppose we'll be doing in gym today?"

"I hope not the weight room," said Lenny. "Guys are sub this week."

"Me too," said Brad. "I hate the weight room."

"I just can't hold my breath for so long," said Lenny. "Some girls are nice, but some will make you hold your breath for the full two and a half minutes."

"Yeah," said Brad. "I have other reasons."

The boys entered the locker room which was full of boys changing out of their regular clothes. Lenny went to his gym locker and changed into the required gym school uniform which, for boys, was a dark blue spandex thong that felt like it was two sizes too small.

Lenny then exited the locker room into the big gymnasium as always at the start of gym class. Spotting Brad, Gary, and Jim, Lenny joined his friends sitting on the partially-extended bleachers together.

The girls were also coming out of the girls' locker room wearing only hot pink thongs and string-bikini tops.

The two gym teachers, Mrs. Fredashay and Mr. Klavierstein, were standing holding clipboards as the students assembled on the bleachers.

"The gym teachers gotta be fuckin' queer to make us dress like this," whispered Gary to the other three.

"Yeah," said Jim as he jabbed Lenny in the ribs with his elbow, "but it's worth it to see the girls almost naked, too."

Gary laughed, but Brad remained sullen.

When all the kids were out of the locker rooms, the teachers took attendance. Then Mrs. Fredashay announced, "Okay class. We're in the weight room today. This week, girls are dom and boys are sub."

The boys all groaned, and the girls all just giggled.

The two teachers led the combined class down a short hallway off the gymnasium into the weight room. Inside the windowless room about the size of a classroom stood four large weight machines, each of which looked like an odd collection of steel beams, cables, weights, and handles extended from all four sides of each one. Four padded benches extended from each of the machines, each about 6" above the floor for a total of 16 workout stations--exactly right for a class of 16 boys and 16 girls.

As the kids all stood around the room. Mr. Klavierstein said, "Okay boys, your choice today. Pick a station and take your place."

Lenny headed for the shoulder press station on the closest machine when Brad said, "Coach, I really don't like doing this."

Mr. Klavierstein glared at Brad momentarily. "What? Are you a faggot? Don't like girls?"

"What if I am?" said Brad.

Lenny walked over to his friend. "Coach, I'm not a f..." He stopped himself before saying the word. "I'm not gay, but I don't like doing this either. It hurts to hold my breath so long. And it's humiliating, too."

Mr. Klavierstein paused in thought for a moment before replying. "Boys," he said, "a little humiliation is good for you. It teaches, er, humility." He pointed to Brad. "Even you, faggot. Besides, how do you expect the girls to work out if you don't do your parts?"

"May I add something?" said Mrs. Fredashay. "You boys are almost all heavier than any of the girls. Yet none of the girls ever complained when it's their turn to be sub."

The girls all shouted, "Right!" and then all broke out giggling.

Feeling defeated, Lenny lay down on the bench at the shoulder press station. The machine was above his head as he stared up at the handles. He watched as Brad climbed inside one of the machines and slipped a thick padded noose around his neck.

"Okay, girls," announced Mrs. Fredashay. "Pick a station and secure your boy."

Lenny's heart pounded as the girls all approached the machines. Sherry came over and knelt by him and shackled his wrists and ankles to the bench, then buckled two straps across his chest and waist. He was trapped and barely able to move.

Mrs. Fredashay then pointed to the timer on the wall. "Girls, you all know the drill by now, I hope. When the clock rings once, you start exercising for two and a half minutes. When the clock rings twice, you lift up to let your boy breathe for 30 seconds. After nine minutes, you rotate around the machine clockwise to the next station. That gives you all a total of seven and a half minutes on each of the four stations during the class period.

Lenny swallowed hard when the clock rang once. Sherry swung a leg over Lenny's body and sat on his face. Her spandex-covered crotch pressed down on his mouth and his nose slipped into her naked ass crack as everything went black and he felt a crushing weight on his skull as she settled down on his face.

A moment later, he could hear the clattering of weights. Sherry's already painful weight bearing down on his face suddenly multiplied as he felt her strain to lift the the weights with her arms.

Her weight increased and decreased in a steady rhythm, as he held his breath. After a short while, his lungs began to cry out for air, but her ass on his face created too tight a seal. The pain in his lungs continued to increase as Sherry continued to exercise. The minutes dragged on. Lenny was kicking and struggling furiously against his shackles, though he was tightly bound and hardly moved.

Finally, the bell rang twice and Sherry stood. Lenny gasped explosively as he caught his breath, staring into Sherry's naked ass above his face straddled between her naked legs. The 30 seconds went by too fast when the bell rang once again, and Sherry sat back down and resumed exercising.

The cycle repeated itself until Mrs. Fredashay announced the rotation after Sherry stood for the third time. He watched Sherry walk to the next station on the machine as another girl took a seat on his face. Lenny didn't even notice who's twat was pressing down on his mouth and who's ass crack had sucked in his nose. All he knew is that it wasn't pleasurable at all--it was painful and terrifying.