Ellen DeGeneres [1] is known for her pranks [2] and scares [3], but her latest joke with Harry Styles looks like one of the funniest yet. On Wednesday's The Ellen DeGeneres Show [4] episode, the "Fine Line" singer was forced to befriend a pizza delivery man, and honestly, it's remarkable that this poor soul didn't walk out after the 60th time Harry called him "bro."

Harry was a pro, sticking to the host's ridiculous script during a hidden-camera prank — and even improvised when she left him hanging. About a cheese fact, no less! That's right, Ellen went totally silent on the earpiece for a moment because she couldn't stop laughing, which meant Harry was on his own. It's a good thing he's quick on his feet. Watch all of the hilarity go down in the video above.