"You can't explain how the ring works," Robert said, "it's magic."
Cassie rolled her eyes. "Well obviously you can't. Now hurry up!" She rolled over onto her back and spread her legs, thrusting her breasts into the air. "I promise, I think better after I orgasm."
"We're supposed to be-"
"Studying? What could you possibly be tutoring me in? No Robert- do you prefer Robert or Robby? Or are you a Bob?"
"Just Robert." Robert looked around the massive bedroom and took in the sights of the lab and the various chalkboards choked with scribbled notes. "Wait, if I'm not tutoring you then why am I here?"
"Isn't it obvious?" Cassie rolled onto all fours and sighed before starting to crawl towards Robert. "A big strapping man like you? Smart enough not to bore me, maybe even help on a few projects?"
"I'm your... assistant?"
Cassie got up on her knees at the edge of the bed. Thanks to the extra thick mattress she was able to look Robert eye to eye. "There are plenty of people that could fill the role of assistant. Someone like you?" She placed her hands on his shoulders and then tracked her fingernails down his musculature. "Sorry Robert, you're my boy-toy." She leaned forwards enough that the tips of her breasts were poking at his chest as she whispered. "Don't worry. I take very good care of my toys."
Without him thinking about it he had his hands on her hips. Her soft flesh felt feverishly warm under his hands as he picked her up and threw her onto her back. She giggled as he placed himself on top of her and bent down to kiss her.
To her delighted squeals he picked her legs up and put them up on her shoulders, bending her in half and giving him a better angle.
"Cum in me this time..." she said between panted breaths. "I'm on the shot, we'll be fine."
Robert didn't wait for other instructions, instead he slid himself into her in one fast motion. Cassie's eyes bugged out and she grunted but not a complaint passed by her lips. Whatever intuitive senses that Cassie had given him earlier were telling him that Cassie liked to be used in the bedroom.
What really surprised him was that she held to her promise of explaining the ring to him during sex. "You see this ring is tech tech blah blah jargon science blah. Oh fuck yes push it in deeper! It uses blah jargon science quantum blah blah multiverse theory oh right there don't you dare fucking stop! The blah blah quarks science science mmm... Micro singularity entanglement blah..." She went on like that. Even if he hadn't been balls deep in one of the hottest girls he'd ever seen Robert doubted he could have followed along. He'd thought he was smart but she may as well have been speaking Chinese for all the sense he could make of it.
"So you see we can cah! CaaaaAAAAHHHHHH!" It wasn't her first orgasm but it did feel like her most intense. As the walls of her vagina clamped down on his cock Robert felt himself blow his load deep inside of her. He hoped she was right about that shot as he could feel him pump what felt like gallons of cum into her, it even spurted out around the sides of his dick.
Cassie loved it, having yet another orgasm as she feel the sensation of herself being filled. She sighed as she felt Robert go soft and slide out of her. Quickly she gathered her strength and rolled forwards to place her face near his softening flesh. She lazily slid her tongue out and started to lick his cock clean. With her extra long tongue it didn't take long and soon she was dragging her tongue along to tip of his cock as she withdrew it back into herself. "Mmm... I taste good," Cassie said before collapsing onto the bed.