John Mayer

John Mayer will take over Watch What Happens Live in honour of host Andy Cohen’s 50th birthday.

The singer and talk show host are firm friends, and Andy even joined John on tour in Brazil so he could be there to celebrate the musician’s 40th last October (17). And to return the gesture, the Grammy winner took it upon himself to give Andy a night off from hosting duties in honour of his upcoming birthday on Saturday (2June18).

“It is so hard to go dark on Andy because we talk so constantly. I couldn’t give away that I was in New York,” John said in a clip of the big surprise online posted by E!. “It was the hardest 12 hours of my life.”

Andy looked floored by John’s arrival, and sat open-mouthed as the singer serenaded him.

Highlights from the songwriter’s presenting stint included cake and balloons, embarrassing personal videos, and many happy returns from members of Andy’s inner celebrity circle including Dolly Parton, Sarah Jessica Parker and Anderson Cooper.

John also joked about the fact that his friendship with Andy allows him to mingle with the Hollywood elite in spite of his colourful dating history – with ex-girlfriends including Katy Perry, Taylor Swift and Jessica Simpson.

“You have a lot of friends who without you would want nothing to do with me, and I find that exciting,” the Gravity hitmaker remarked. “I don’t have the greatest track record when it comes to celebrity relationships, so it’s amazing to watch your friends humour me on a friend level but also keep a fair distance from me.”

He added that “dating John Mayer at this point is conceptually just sort of a no-no” for any A-lister who cares about their reputation, and proceeded to thank Andy for allowing him to spend time with people “who otherwise would be highly uncomfortable sitting around” him.

Watch What Happens Live: Andy’s 50th Birthday airs on 3 June.