Walter in a swimsuit

That faithful day, Tim was standing in front of what looked like a young woman wearing a swimsuit inside his dorm room.

"Dad, if I had not seen you change a few minutes ago, I would not believe it! But why this? Isn't that illegal or something?" Tim asked.

"Son..." the mentioned started. "It's not illegal because this body is 18!" it came out in a male voice.
"Also, how do you like my ass?" it came next and the apparent girl turned around.

"Dad, did the device screw with your head or something!?" Tim yelled.

"No, son. It's just the teenage hormones..." came the not quite believable response.

Just then, Tim noticed that something was happening in his pants...