Photos emerged of Piers and his wife Celia Walden seated inside the back of a cab, taken by the paparazzi.
While Celia, 45, had her face covered in a patterned mask, Piers, 55, forgot to put his on, breaking the guidelines in preventing the spread of Covid.
Piers apologised for the misstep, but it didn’t stop his colleagues from seizing the opportunity to have a go at him.
His GMB co-star Charlotte Hawkins couldn’t help but poke fun at him on the show, buying him a bespoke face mask as a cheeky dig.
Emblazoned across the front of the mask were the words “wake up,” inspired by his new autobiography.
Susanna Reid also waved a copy of the Daily Star, where the front-page splash showed the picture of a mask-less Piers.
He exclaimed: “There’s the front page of the Daily Star, which is me being caught without a mask.
“Masks are important, don’t take it lightly, and I’m sorry.”
At the beginning of the Monday installment of GMB, Piers leaped into the story behind the photo, explaining he’d been chatting with the paps before climbing into the taxi.
The presenter claimed he’d been distracted by their conversation, and only realised he’d forgotten his mask when the car sped away.
He said: “It was only as I pulled away that I realised that I’d forgotten to put my mask on and had therefore designated myself as a Covidiot.”
Piers held his hands up and apologised to viewers, saying: “I was nailed and I can only apologise.”
He eventually repeated the apology, saying: “I got caught for that one. It’s not a good look, and I apologise.”
The dad-of-four then revealed Gary Lineker, who was similarly caught without a mask, reached out to him after hearing the news.
Good Morning Britain airs on weekdays at 6am on ITV.