Robert tried hard to be a good dad for his daughter. Being a single parent is always difficult, but for Robert it was particularly hard since he never was very… good with people. His head was always in the cloud, constantly focused on his science and his wacky inventions, and that wasn’t really a good premise for raising his teenage daughter on his own. They ended up growing further and further apart as years went by, so in the end they had become like strangers to each other. Robert was obviously sad about it, but he knew that if he succeeded in completing just one of his inventions he could have given his beloved daughter a future of wealth and stability. So he kept focusing on his work, knowing that sooner or later he would have achieved success. He didn’t know how close he was to his goal. Nor that in a couple of hours he and his daughter would have been closer than ever.
When she got home with her friend they both barely greeted him, and just headed straight for her bedroom to study as always. Robert wasn’t even offended by that lack of consideration, he was too absorbed by his work. It was finally complete. His revolutionary body swapping machine. Oh, the fame and success that invention would have brought him, the things humanity could have achieved with it! If it did work that is. All that was left to do was test it on humans, but Robert didn’t even know where to start with that. Then he realized he could have tested it on himself, and try to swap with his daughter’s friend. Surely he would not have minded if he borrowed his body for a while. It was all for science after all. So he set the dials, connected the wires and put on the helmet. Soon he would have felt young and energetic again. It would have been fun to take a break from his out of shape middle-aged body. He pulled the switch and felt reality warp around him.
When he got back to his senses and felt the weight of a body again he was more thrilled than he had ever been in his life. He was in his daughter’s bedroom! The machine had worked! Finally after all those years of failures he managed to create a machine that actually worked! He was so excited and filled with glee that he didn’t even realize at first that he was laying naked on the bed. Nor that he was not in the body he planned to end up into. Only when he raised to a sitting position, and felt long hair brushing against his shoulders and back, and rubbed his smooth and toned legs and his tights together without anything getting in the way, and felt two mounds of flesh wiggle on his chest, he realized that something was off. His heart skipped a beat when he looked down at his dainty hands with nail polish, and at the perky breasts hanging from his chest, and at his new flat crotch, and he would have screamed in terror if he had not been way too overturned to even let the faintest sound escape his luscious lips. He looked at his reflection in the mirror hanging on the wall, and had the dreadful confirmation of what had just happened. He was in his daughter’s body.
So the machine was only a partial success. While it allowed him to swap bodies with someone, its guiding system had still to be perfected. He would have taken note immediately of all the adjustment to apply to the machine, just as he would normally have done, if he hadn’t been way too unsettled by the alien feeling of his new body. For the first time in a long while he could not focus on his science, and was instead overwhelmed by those sensations. That day he not only realized that that guy and his daughter were more than just friend, but judging by the soreness of his new genitals and by his feeling of exhaustion he could tell that his daughter wasn’t still a virgin as he thought.
Before he could have done anything the guy stepped out of the bathroom and into the room, naked, and with a throbbing hard-on. <<So babe, ready for round two?>> Robert could not do anything besides sitting still in disbelief. Only then he became lucid enough to realize how disturbing and wrong it was to be trapped inside of his own daughter’s naked body. He should have rushed to the basement where the machine was, and try to figure out immediately how to return to his body. But in that moment all he could focus on was the guy’s throbbing erection. Whatever his mind was commanding him to do, his new body was very much inclined to completely ignore it, and just keep focusing on that shaft and all the fun things he could have done with it. His scientific mind wasn’t in control any longer. His new body and its new urges and instincts were. And so he decided to let them guide him. After all he could have always taken advantage of the experience, as an experiment aimed at finding out how a different body felt.