"Carrot or Stick" is the tenth episode of the seventh season of the American medical drama House.
It appears they have a genetic disease, and House eventually concludes it's variegate porphyria.
He first visits the school under false pretenses, takes pictures of all the toys in the test room and buys several of them.
Also, Chase faces some personal troubles after a full-frontal nude photo of him, photoshopped to make his penis look much smaller than it is, is posted on his own social networking website.
He suspects one of the girls he had sex with after a wedding (episode 8, "Small Sacrifices") has taken the photo out of revenge for his lack of interest the morning after.