Step-brothers spends full of the weekend eating pizza and hamburger, so they feel their belly button exploting.
They call Dr Fer who starts the treatment watching how ups and down his belly button, then uses things to put in belly button to see if they feel better, including toothbrush and playing with their piercings touching with a tool. After that lick their belly button but nothing happens, so dr fer goes and they have to touch their belly button and feeling the other, getting horny.