Zack hears them as he washes his trunks

Zack was in the hall bathroom, feeling awkward as he washed the cum out of his swimming trunks. He sighed as the last sticky gob of pearly stuff rinsed out of the nylon. He turned off the sink and twisted the trunks, wringing out the water.

Now that the water was no longer running, he could hear the girls still going at it, the mattress squeaking at a rapid pace.

"I'm cumming, Hannah!" Heather cried out. "I'm fucking cumming from being fucked by a girl with a fucking fake cock!"

"I'm cumming too, Heather!" Hannah cried out.

As Hannah and Heather screamed out their orgasms together, Zack felt his cock throb and stiffen again. He shook his head and kept squeezing out the water from his swimming trunks until they no longer dripped. He put the damp trunks back on over his still-firm erection and wrapped a towel around his hips to hide it. It'd go down soon enough, he figured.

It was quiet when he opened the bathroom door and looked back into the hall. The girls' door was open a crack. Zack supposed it hadn't quite latched when he tried to beat a silent retreat.

That open space beckoned. The devilish impulse that had made him open the door in the first place returned. He had to look.

Heather was stretched out nude between Taylor and Hannah. Hannah was still wearing her harnessed dildo. The scent of girl, girl, and girl tickled Zack's nostrils as he looked. His hand held the door handle. He could, he should just close it. He could tell the folks at the lake they were napping, or they needed Heather for some girl stuff or for help setting up the bedroom. His erection throbbed, pressing out at the confining swimming trunks and towel. He could feel the pulse beat in his veins, and his face felt warm.