Every year Jimmy Kimmel Live issues a Father’s Day YouTube Challenge. In years past, viewers have been asked to spray their dad with a hose, throw a pie in dad’s face, serve him breakfast in the shower, etc. This year’s challenge was simple: sneak up on dad and yell “I love you Dad” as loud as possible.

“I was starting to think this might not work but I was very very wrong,” Kimmel said.  Best of results were presented on Monday night’s show.

When Kimmel announced this year’s challenge, he warned: “You can do this while he’s sleeping, eating, just don’t do it while he’s driving or shaving. Don’t kill or injure your father.”