"How about we swap body builds" Jon said.
"body builds, what exactly do you mean by that?" Karyn said.
"our bodys bone and muscle mass and structure. things like your slender limbs and wide hips for my broad chest and shoulders and jawline"
"But i'd have man hands" karyn said in disgust.
"yes, you'd look like an unpassing tranny and i'd resemble a flat chested girl with a dick. But it's only for a week."
"well... ok" Karyn reluctantly agreed
"I wish for the next seven days me and karyn swap body builds including muscle and bone structure".