Between her thighs

"Okay, part two of the experiment," Robin announced, trying to sound like a dispassionate lab technician despite the fact that his heart was currently attempting to beat its way out of his chest. He kept his eyes strictly on the spray nozzle, refusing to look at Sophie’s face. "We need to test... lower extremities. To see if the fabric density is different down there."

Sophie, hugging her knees to her chest and sitting on the edge of the tub, nodded miserably. "Just get it over with, Robin. But be careful. I don't want water going... you know... everywhere."

"I'll be precise," Robin promised, adjusting the setting on the showerhead to a gentle, pulsating massage spray. "It's just water, Soph. It's physics."

He aimed the spray at her legs. To Sophie, she was wearing an oversized tshirt that extended just past where her panties would be, if she was wearing any. She watched the water pulse into the soaked fabric, shifting it up her thighs. To Robin, however, the spray hit her pale skin directly, beading up on her toned legs and running down into the crevice where her thighs met her hips.

"Okay, observing runoff," Robin muttered, his eyes involuntarily drawn to the apex of her thighs. The water was cascading over her mound, dripping down her slit. It was mesmerizing and terrifying. "Does it feel like it's hitting the shirt hem?"

"It feels wet," Sophie said, her voice tight. "It's soaking through."

"I need to get a closer look at the... hem," Robin said, taking a half-step forward. He angled the nozzle upward, unintentionally letting the water jet hit her directly in the center of her groin, just below where the hem of the invisible shirt would be.

The pressure of the water hit her exposed labia.

"Ah!" Sophie gasped, her legs twitching instinctively. "That's... that's a bit strong!"

"Sorry, sorry!" Robin said, but he didn't turn the spray off. Instead, he twisted the dial slightly, changing it to a different rhythmic pulse. "Just checking if the water gets trapped by the fabric or runs off. It looks like it's running straight through."

To him, it looked like he was deliberately spraying water onto her most private area. The water splashed off her clit, sending droplets flying onto his shirt. "I can see... everything, Soph. The water isn't being blocked at all. It's just flowing right over... it."

"Robin, move it!" Sophie cried out, squirming as the pulsating water stimulated her sensitive clit. It felt intense, overwhelming, and entirely too intimate. "It's too sensitive!"

"Dont move it, just grab a washcloth!" Viki suggested from the other listen, her scientific brain latching onto a solution that wouldnt backtrack Robin's progress. "If you cover up with the washcloth, Robin can see if the water pools on top of the fabric instead of hitting you directly! It's for protection!"

"Right! Protection!" Sophie agreed, frantically grabbing the fluffy white washcloth she had dropped earlier. She pushed the washcloth down between her legs, pressing it firmly over her crotch to shield herself from the intrusive spray. "There! Is it covered?"

Robin stared at her hands. She was pressing a cloth into her groin, but to him, she was just cupping her own sex. He could see her fingers pressing into her soft flesh, but there was no white fabric visible. Just her hands and... everything underneath.

"I can't see it," Robin said, his voice breathless. "But I can see your hands pressing it against you. Okay, I'm going to spray it now to test the barrier."

He aimed the showerhead at her hands.

Sophie yelped as the water hit the back of her hands, but she held the cloth tight. The spray **** its way through her fingers, soaking the invisible washcloth and pressing it tighter against her clit. The rough texture of the terrycloth, combined with the relentless vibration of the water, sent a jolt of electricity through her.

"Robin!" she gasped, her hips bucking slightly. "The water... it's vibrating!"

"I see that!" Robin said, stepping closer, his eyes glued to the spot where her hands met her body. "The water is hitting the cloth, but I can't tell if it's holding up. I need to verify the integrity of the barrier."

Before Sophie could protest, Robin reached out with his free hand. "I'm just going to feel for the edge of the washcloth. To make sure it's positioned correctly."

He placed his hand over hers.

The moment his skin touched hers, Sophie froze. Robin didn't feel terrycloth immediately. Instead, his fingers brushed against the smooth, wet skin of her inner thigh. He slid his hand upward, searching for the fluffy texture of the washcloth, but his fingers slipped on the water.

"Where is it?" Robin muttered, concentrating hard. "I can't find the edge, Soph. I need to feel..."

He pushed his fingers under her palms, trying to locate the cloth she was pressing against herself. In doing so, he inadvertently shoved her own hands aside, his fingers sliding directly into the hot, wet space between her legs.

"OH!" Sophie squealed, her eyes going wide. "Robin! That's not the cloth!"

Robin froze, his fingers now buried in the folds of her labia. He could feel the heat radiating from her, the slickness of the water mixing with her own arousal. He had meant to grab a washcloth, but instead, he was cupping her naked pussy.

"I... I think the cloth slipped," Robin whispered, his face burning. He tried to pull his hand back, but the showerhead was still spraying water directly onto his hand and her privates. The **** of the water caused her to snap her thighs shut, holding his hand in place, pinning his fingers against her sensitive flesh.

"Aaahh!" Sophie gasped, her breath coming in ragged bursts. The sensation of his fingers, warm and calloused, pressing against her clit, combined with the stinging spray of the showerhead, was creating a pressure cooker of sensation. "Just... just make it stop!"

"I can't let go!" Robin panicked, his thumb accidentally brushing over her clit as he tried to find a grip to pull away. "It's too slippery!"

"Robin!" Sophie cried out, her head falling back as a wave of pleasure crashed over her. "That... that feels...!"

"I'm sorry! I'm trying to find the cloth!" Robin insisted, his fingers wiggling in the wet heat. He felt a swell of panic as he realized he was essentially groping her by accident. The water was gushing over his hand, running down his wrist, and he could feel her muscles clenching around his fingers

To Robin, it looked like he was fingering his roommate under a faucet. To Sophie, the friction of the invisible washcloth—which was somehow rubbing against her at the same time—combined with Robin's clumsy, frantic fingers, was pushing her toward an edge she hadn't expected.

"The water!" Sophie gasped, her hips jerking uncontrollably. "Turn off the water!"

"Okay, okay!" Robin fumbled with the faucet with his free hand, but in his haste, he accidentally sprayed her again, sending a jet of water directly onto his hand and her exposed clit.

"AHH!" Sophie shrieked, her body convulsing as the stimulation peaked. Her toes curled against the porcelain of the tub, and her inner thighs squeezed Robin's hand tight.

Robin finally managed to release the valve, cutting off the flow. Silence filled the bathroom, broken only by their ragged breathing.

Robin stared at his hand, which was still trapped between Sophie's warm thighs. He could feel the rapid thumping of her pulse through the sensitive flesh of her groin.

"I think..." Robin croaked, slowly withdrawing his hand, trailing a string of wetness as he pulled away. "I think the water definitely feeds into the curse. It made me lose track of washcloth entirely."

Sophie sat slumped against the wall, her chest heaving, her face flushed a deep, dark red. She looked down at her bottomlessness, then up at Robin, whose hand was dripping wet, partially due to her own wetness she knew.

"Data... collected," Sophie wheezed, unable to meet his eyes. "Can we please... dry off now?"

Robin swallowed hard, looking at his hand, then back at her, a look of pure, unadulterated shock on his face. "Yeah. Dry off. Good idea. I'll just... go find a towel. A visible one."

He backed out of the tub, nearly tripping over his own feet, and fled the bathroom, leaving Sophie alone to process the fact that her roommate had just accidentally given her the most intense physical sensation of her life while trying to do science.