Ellen DeGeneres teamed up with Bruno Mars to pull a prank on an unsuspecting nurse.
Mars wore an earpiece in which he could hear the talk show host, and had to do everything that she told him to.
The singer said several ridiculous things to Deborah, the nurse, including that he had not swallowed since the Super Bowl, before revealing that she was on The Ellen Show.
Watch the full clip above.
Follow Carrie Healey on Twitter @CarrieHeals.