Alex was a mostly normal guy. He picked up the weird device, thinking that it most likely wouldn't work at all. It would be an interesting thing to think about. And if it did work he would be able to have some interesting experiments.
He always wanted to experience what it would be like having a completely different gender, and since he was bi he thought it would be pretty interesting to sleep with one of the new sexes. And if he really didn't like it, he could always just bring things back to normal.
He knew that whatever he did would have a big effect on the world. Not only would it change gender and sexuality as we know it, it would do it in revese as well, so the entire world would have always been the way that he made it. It was a lot to deal with.
He got back to his apartment and started to think about how he could change the human race. He prepared to make his alteration...