A second alien entered the room and watched him pump and thrust. Nicholas tried to stay focused, building up a steady rhythm. From their vantage points, the aliens seemed fascinated watching his erection slop in and out of the doll's clear vaginal canal. One alien reached out a tendril to touch his flopping balls. Another alien twirled its tentacles down Nicholas's spine, seemingly taking measurements, taking his pulse, as he arched his back with each thrust.
Out of habit, Nicholas adjusted his legs together - his girlfriend liked to wrap her legs around his hairy thighs and hold his ass while he planked/fucked, but the aliens did not want to be denied the view, so they wrapped a tentacle around his ankles and forced his legs apart while he pumped. The aliens were fascinated with human anatomy, the dynamics, the design.
Nicholas looked up and on the previously featureless white walls were now screens broadcasting his thrusting from many angles. He was more than a little turned on to watch his penis slide in and out of the transparent vagina, swelling in girth, reddening with motion. And the view from above, well, it was hot watching himself fuck like looking up at a mirrored ceiling.
A white alien laboratory did not seem to be the best erotic places to have sex, but Nicholas dutifully pumped in and out of the doll, until he knew he was close. He gasped, "I'm going to cum!" And the two aliens raced to add sensor pads down his spine, down his neck, down the back of his legs.
At one point, one of the aliens stood at the foot of the table with a tentacle holding his balls, other tentacles wrapped around his toes and ankles. The other alien was at the head of the table spewing its tentacles to hold his fingers and wrists, wrapping another tentacle around his blushing neck. Then, the two aliens hoisted poor Nicholas by the ankles and wrists, flopping him up and down the way you'd make a bed by flapping the sheets. But this odd flapping gesture only made the young man's penis repeatedly pop out of the doll's vagina, so the aliens let Nicholas go to return to his steady missionary posture.
Nicholas panted, grunted and struggled and had an instance of embarrassment, wondering how his "O" face would look to the aliens. But he was soon shuddering with release and delight and watched as his ejaculate pulsed into the doll filling many transparent channels inside. He spurted a number of times, controlling his instinct to pull out and cum on its belly like he would with a human girl. When he was done, he began to pull out, but an alien held his ass in place. They wanted every last drop.
Finally satisfied that he had delivered his complete load, the alien withdrew its tentacle from across his buttocks. Another tentacle released his scrotum, his other extremities. Nicholas got up to his knees, looked at the pool of his semen inside the doll's innards - a transparent replica of the uterus and fallopian tubes, and got off the table. He realized he was still dripping cum from the end of his dick, but an alien tentacle tubule quickly suctioned him off. Another alien was removing the sensor pads from his back, a tentacle sniffing his sweaty body like a curious elephant trunk.
Nicholas looked around the room, wondering what would happen next. Finally the darker of the 2 aliens handed him a food cube and transmitted to him, "Well done."
