You suddenly are standing right where your mom was standing and you see yourself sitting on the couch. You look down and you are wearing your mom's work clothes, and you see two average sized mounds on your chest.
You look up again when your body laughs. "Funny, isn't it, Jack? Now you're the one who has to do the work! It dawns on you that your mom somehow switched your bodies!
"Ok, mom, I don't know how you did this, but switch us back! " you plead.
"Sorry son, but I can't do that. I cast a spell that lasts just about... forever! "
"But... you can switch us back, right? "
"Nope! So get used to your new body... Barbara! " the look on your mom's, well, your face is of absolute glee.
"But mom, why me? " you ask, "why not Jenna or... I'm not cut out to be a woman! " "You're going to have to be Jack, because this is your new life!"
"Mom, I don't have the slightest idea how to be a woman!
"Then I'll teach you, " she says, "and don't call me mom."