Naomi was furiously masturbating in one of the stalls, enjoying herself with her eyes closed when Rachel came in the swimming pool's bathrooms.
"Are you okay?" Rachel called out to her friend.
Naomi's eyes opened wide and she froze, letting go of her hard rod. She looked down at her condition; her erect penis was sticking out of her swimsuit and leaking clear fluids over itself. Her hands were sticky as well and she looked around for toilet paper in a hurry.
"Yeah! Just feeling under the weather is all, don't worry about it", Naomi replied while wiping her twitching appendage and trying to calm down.
"No problem. If you want we can just head to the showers and leave, we can do something else together" Rachel went on, as Naomi took a big inspiration trying to stuff her prick back into her suit. After struggling for a hot second, she realized it worked better if she guided the length upright on one side near her hip rather than trying to shove it back down.
When she was confident that the skirt of her suit was hiding her erection, she wiped her hands once more and excited the stall awkwardly.
"Yes, I think it would be best. Sorry for ruining the fun here!" Naomi said with red on her cheeks, trying to not sway the skirt too much as she walked.
In the showers, Naomi did her best to keep her front turned away from Rachel. Unfortunately, her hard-on wouldn't die down. On the brighter side, no one else was around. She hoped to rince without being noticed and change discretly in the changing stalls.
Taking a peep over her shoulder, she could see Rachel wash the chlorinated water away from her own body, rubbing her thighs and breasts vigorously. Naomi felt her heart race and her shaft throbbed once more, pushing against the waistband. Glancing down, she watched in horror as the head slipped past and lifted itself high against her belly.
"I'm sorry this hasn't been fun for you Naomi", she heard Rachel say comfortingly. "I hate seeing my best friend unwell".
At this moment, Naomi felt Rachel's arms hug her from behind and squeeze her affectionately. She almost let a whimper out when her friend narrowly missed brushing against her erection. She instantely placed her hands over Rachel's to guide her higher up on her body, leading her away from accidental discovery.
Rachel hesitated for a second, and misinterpreted Naomi's gesture as encouragement. She slowly slipped her hands on Naomi's breasts and began fondling them, kissing the back of her neck. Naomi moaned in pleasure and surprise, and she felt her balls tighten.
A thick rope escaped her hard pole and splattered on the tiles, immediately washed away under the shower. She tried to muffle a lewd moan, watchling helplessly the geyser of white gunk spilling over itself, onto her skirt, and down the drain.
"Rachel, I-" she started, panting but unable to stop herself. Rachel lifted the top piece of her suit up, freeing Naomi's breasts and grabbing them sensually. Naomi's nipples hardened under Rachel's touch and the splashing water droplets.
"It's ok Naomi. I've seen how you look at me, I know you want this. I want it, too." Rachel whispered against her ear.
Naomi didn't know what to answer. She had one hand over one of Rachel's hands, and the other down the front of her groin to push her spasming penis back into the swimming suit as discretly as she could.
Pinning the dying erection down under the skirt, she was trying to think of a good answer when Rachel turned her around and kissed her languorously.