on loan: the begining

Jon and Karen sat on his bed, the rock in between them glowed. "What should we wish?" Jon asked "Wanna try an experiment?" Karyn asked "What?" "What would you like to trade?" "Huh?" "Well I thought maybe we could trade something that the other sex has, like swap chests. You can have my cleavage; or we can swap genitals, hair, or I could loan you my womb. I would love to have sex without worrying about having a baby." Jon thought for a moment,"if we do a time limit. I'm not playing for keeps." "Alrighty then!"