One start-up just learned the hard way not to mess with the gang from Sesame Street.



Mately, a STD-testing site and app, ruffled Big Bird's feathers earlier this week after it posted advertisements featuring Bert and Ernie from Sesame Street that suggested the pair were romantically involved, according to the BBC.

The ad, based on a viral internet meme, ran with the tag line: "See Ernie, you've got nothing to worry about, everything is positive!"

"The Mately ad is an unauthorized, unlicensed use of our characters," Sesame Workshop told the BBC. "We will be contacting Mately and the appropriate parties with a cease and desist letter instructing them to take this down.