Gerard Butler & John Mayer: Birthday Duet!

Gerard Butler celebrated his 41st birthday by singing “Mustang Sally” with John Mayer on Friday (November 13) in New York City.

The 41-year-old Scottish actor rented out The Darby in Midtown, New York for a crowd that included Adrien Brody, Kate Hudson, Bono and Jay-Z. Cabaret star Lady Rizo aka Amelia Zirin-Brown was the night’s emcee, who said, “Some of you know him as Gerry, other as Gerard. I know him as Mistress Butler,” according to Page Six.

Gerry sang the Oasis hit “Wonderwall” first, before asking John Mayer to join him onstage. John also ended up singing his hit “Who Says.”