Professor Frink invited Burns and Smithers to prove a new experiment. He said that it'll be harmless, so he have not worry about what happen. He then uses a machine (or a Chemical potion, whatever), and wait.
Then...
"Wow!!", Burns and Smithers shouts at the same time, obviously surprised.
Nothing strange until Burns spoke... with Smithers' voice!
"Sir! Look, I'm in your body! Oh my it's awesome!", he said with a huge delightful face and light blush on his cheeks.
"Waylon Smithers Jr.!", Burns (Smithers) whatever seems disturbed and quite angry. "Stop making those faces with my face RIGHT NOW! And stop making me touch myself in this instant!"
"But sir! Think now in all the possibilities! You're now young ang strong; you can do anything! While I can do anything with this body", it seems that the change excited him a bit too much. Like one of his fantasies went real.
"I don't want to discover what it's is", Burns grab his own tie and make eye contact. "I feel so weird in this body; and you!", shouts at Professor Frink. "You better squeeze that brain of yours and CHANGE. US. BACK"
"Sorry my friends, I don't make yet an antidote for this. You better stay here until I found one"
"Oh my... that's great!", Burns signs with sarcasm, watching Smithers admiring his new body.
What will happen next?
C. Montgomery Burns, Waylon Smithers Jr. and Prof. Frink (c) Matt Groening