Bruno Mars took the stage on 'Ellen' to perform 'When I Was Your Man' -- and the hostess with the mostess revealed that it's the only place he'd do so. What an honor!

Mars rocked a fedora and shades for the stripped down show, which featured just the 'Unorthodox Jukebox' singer at a red piano. His performance was heartfelt, and when combined with lyrics so heartbroken, Mars was particularly moving. He almost had a Stevie Wonder vibe going -- no easy task, especially not for someone so new.