British model Suki Waterhouse's wardrobe malfunction almost resulted to a nip slip as she donned a revealing dress while attending the Serpentine Galley Summer Party. Her boyfriend Bradley Cooper, meanwhile, was caught staring at the model's exposed cleavage.

The 22-year-old Suki Waterhouse wore a rose-colored sundress with a wide neckline that created a wide possibility of nip slip. Her cleavage was also exposed as her nipples poked through the thin Burberry clothing of the model.

The E! Online said, "Sometime it's hard to tell if a celebrity is just selecting a sexy outfit or if a full-on wardrobe malfunction is the ultimate goal."

Noting that it is possible to let a gust of wind create a Suki Waterhouse wardrobe malfunction, E! Online speculated that there was an adhesive tape so the neckline will stay on its area.

The model matched her dress with a platform heels from Topshop as she went with a nude make-up. She let her blonde tresses down to her shoulders. She also added a small gold bangle accessory to her right hand.

Meanwhile, her 39-year-old boyfriend, "Silver Linings Playbook" actor Bradley Cooper, went for a dark navy suit and light blue button-up dress shirt, the Daily Mail said.

While laughing and posing for some photo opportunity, Bradley Cooper was caught taking a glimpse of the Suki Waterhouse's wardrobe malfunction that exposed the model's cleavage.

Suki Waterhouse and Bradley Cooper were just some of the A-listers who attended London's Serpentine Galley. Also spotted in the event were British supermodel Cara Delevingne and actress Keira Knightley with husband James Righton. "Happy" singer Pharrell Williams and Princess Beatrice were also there for the occasion.

Bradley Cooper left early leaving her model girlfriend behind as he opted to spend the rest of his night at the Glastonbury with pal Michael Fassbender and former Oasis guitarist Noel Gallagher.