Chrissy Teigen has admitted she had sex with John Legend at a Barack Obama event.

The 29-year-old model left her husband speechless after she revealed at the Grammy Awards they had once got frisky at a public function for the president, prior to his election in 2009.

When asked by AJ Calloway and Tracey Edmonds from 'Extra' to reveal whether the most public place they got intimate at was their best or worst experience, John hesitantly replied: ''The best.''

But Chrissy took it one step further by announcing on the red carpet at the glamorous event on Sunday (08.02.15): ''Okay, the best, um, probably the Obama thing,'' before walking off camera.

The 'All Of Me' hitmaker, 36, seemed puzzled by his wife's answer, before saying, ''I don't know [what's she on about]. We're not going to discuss that. We're not talking about it, that's the truth.''

The Sports Illustrated babe then jolted back on screen to assure everyone the naughty pair didn't do the deed in the White House.

She confirmed: ''Not the White House. 100 per cent not the White House.''

John added: ''It was not at the White House. That's correct. He was not elected yet.''

However, noticing that she may have embarrassed her handsome spouse, Chrissy apologised for her public outburst, saying: ''Sorry, I'm in trouble now.''

Meanwhile, the gorgeous couple, who got married in 2013, landed themselves on the best dressed list at the awards after they stole the show with their impeccable dress sense.

The brunette beauty had opted for a white figure-hugging floor-length gown with revealing cutouts up the side, while the singer went for a grey suit and crisp white shirt.