You Can't Do That On Television was a Canadian sketch-comedy television series for kids aired on Nickelodeon in the United States. It was created by Roger Price and Geoffrey Darby, and produced at CJOH-TV in Ottawa, Ontario, from 1979 to 1990.
The series' most enduring gag was the "green slime" which poured down from above on any cast member who uttered the words "I don't know." Likewise, saying "water" or "wet" would result in the person who uttered the words being drenched from above with cold water. The green slime remains a trademark of Nickelodeon to this day, although they rarely acknowledge the TV show that invented it.
In "Fast Times at Buddy Cianci Jr. High", Peter Griffin gets slimed when he says, "I don't know," after Lois asks him if Mrs. Clifton is returning to the classroom. The following shot, of a man with the words "You Can't Do That On Television" stamped over his face in red lettering, is also a direct reference to the show's opening sequence, which featured the words stamped on a likeness of the show's star, veteran character actor Les Lye.
"You Can't Do That On Television, Peter", despite its title, includes no obvious reference to this TV series.