"Have us swap genders. So you are a girl and Im a guy" said Jenny
"That should be fun" said Jeff inputting the info in the device and pressing enter.
After a flash both of started to change gradually. Jeff's hair grew while Jenny's shrank. Jenny's breast were shrinking away while Jeff was getting a pair but at the same time he felt his manhood shrink into nothing while Jenny got one. His muscle tone was diminishing as he became more lean. His face was becoming feminine, while she was gaining muscles and her face looking masculine. Their heights were also changing but not much as Jeff shrunk a bit while while Jenny grew. Before long Jeff was a girl and Jenny was a guy.
They were shocked to see each other as the other gender. But soon noticed Jeff's room was now that of a teenage girl's room. The device had changed reality so they were born the opposite gender. They both looked at their ids to see Jeff was now Jessica or Jess for short. While Jenny was Jimmy.
"Oh my god. It worked. Im a guy" said Jimmy aka Jenny
"Told you. Now lets turn back. Being a girl is weird" said Jess aka Jeff