Chrissy Teigen and John Legend. Picture: Instagram

John Legend got "wine drunk" and sung "All of Me" on stage in the middle of Universal Studios Hollywood on Friday.

The "Ordinary People" hitmaker was at the Universal Studios Hollywood when the "Lip Sync Battle" star documented her husband belting out his hit single "All of Me" - which is about her - on what appeared to be the CityWalk stage in the park's shopping area.

Chrissy captioned the Twitter clip: "John got wine drunk and sang a song at universal studios last night.

"The whole joke was supposed to be that literally no one was watching or at the stage but then he got on stage and was like ITS ME JOHN LEGEND. (sic)"

The 40-year-old star was sporting a red onesie with his face on the front of it.

At the end of the video, John - who was singing a little off key - walked off stage, and said: "Thank you."

The singer and model's two children - three-year-old Luna and 17-month-old Miles - didn't appear to be with the couple on their spontaneous night out.

On what inspired "All of Me", which was released just before the pair tied the knot in September 2013 - John explained previously: "The song is saying things that balance each other out: even when I lose, I'm winning; my head's under water, but I'm breathing fine; I give you all of me, you give me all of you

"At the same time as you're giving everything up, you're gaining everything, and that's what the whole song is about. If you're in love and you connect, then even when you're giving things up, you're gaining so much from it."