Whoops! Gigi Hadid had a bit of a nip-slip on the runway

Los Angeles - Gigi Hadid's breast popped out on the runway at Milan Fashion Week.

The 20-year-old model - who is dating former One Direction hunk Zayn Malik, 23 - walked for Versace on Friday and shocked fans sitting on the front row when her low-cut dress slipped down and revealed her right boob.

Rather than quickly fix the unfortunate wardrobe malfunction, the stunner marched on, and a source recalled to Page Six: "That was even more Gigi than Versace paid for, I bet! They got some bang for their buck with that casting. It was literally the longest runway I have ever seen at a fashion show ever, and she had to walk half of it with her boob out."

Rather than be embarrassed, the blonde beauty laughed off the incident like a pro and said on Twitter afterwards: "Malfunctions happen on the runway everyday of fw & are...unfortunate,lol,but let's talk instead about the new VERSACE CHOKERS.(sic)"

Meanwhile, Gigi features in sizzling bikini shots in the latest swimsuit edition of Sports Illustrated magazine and revealed she texted her "special someone" when the magazine went to print.

Referring to her new beau, she shared: "I texted my special someone, I always get excited about the pictures...

"He obviously liked the pictures."

Gigi seemed to take it well as she later took to Twitter...