The boys stood behind the girls.

The girls did not protest that their necklaces and bracelets were green -- they knew it was part of the job that they could be fucked by guests (and occasionally some of their male co-workers) should their gems randomly changed to green. However, this was the first time that all three of them had their gems turn green simultaneously.

"I guess you're going to fuck us now," Valerie giggled as she and her friends stopped their treadmills. After they pulled down their shorts and g-string panties, the girls held on to the handle grips, and bent over.

"Fuck yeah!" Chad cheered, fist bumping his buddies. They whipped out their erections while they walked up to the treadmills -- Chad stood behind Loretta, Brock behind Valerie, and Lance behind Connie.

There was no ceremony or foreplay -- everyone in the gym was there to fuck or be fucked -- and the girls let out loud grunts of approval when the boys anxiously sank their cocks into their pussies.

"Fuck me!" Valerie growled, staring Brock back in the mirror. The quarterback gripped her wide hips and pounded away but she demanded to be fucked harder.

Chad held onto Loretta slender waist and hammered her cunt, causing her to moan appreciatively.

Lance rested his hands on Connie's ass cheeks, parting them so he could see her puckered starfish and her pussy lips sucking in his pistoning cock.

The boys kept pounding away even after the girls climaxed but paused momentarily when the girls, with weakened knees, fell to their hands and knees onto the treadmill.

"God, it's so good to be finally fucked by young studs!" Valerie cooed as Brock squatted over her upturn ass.

"Bro, mind if I fuck the blonde?" Lance asked Chad.

"Yeah, let's switch up, dudes," Chad agreed. "Girls, lie back."

The boys pulled their slick erections from the girls to allow them to flip over and lie back on their towels laid on the treadmill belt. Lance took his place between Loretta's thighs while Chad knelt between Valerie's and Brock between Connie's. The girls let out moans of appreciation when their pussies were filled with cocks again.

The boys kept pounding away until the girls came again and partners were swapped and positions changed.

"Best exercise in a gym, dudes!" Chad cheered, fist bumping his buddies while the girls wildly bounced up and down on their cocks. Even when the girls came and wanted to collapse on top of them, the boys held them up and thrust upwards to continue fucking them to another orgasm. It was only then that their pussies were finally filled with spunk.