Sienna Miller revealed more than she intended when she stepped out with fiance' Tom Sturridge on Thursday.

The couple went to dinner with British fashion designer Matthew Williamson in London on Aug. 15 and had their arms wrapped one another as they were snapped by paparazzi. The Alfie actress wore a sheer black-and-white print top with black floral pants. Unfortunately for the 31-year-old, the flashes from photographers' cameras revealed in the photos published on wesbites she was not wearing a bra.

In the photos of Miller published in PopSugar, she unknowingly flashed her nipples.

View the close-up photo of Miller's wardrobe malfunction here.

The Factory Girl actress has been dating Sturridge for two years. She welcomed their first child, a daughter Marlowe, in July 2012, according to Us WeeklyThe mother-of-one recently shared she is taking a break from filming movies to focus on motherhood.

"Unless it's of that caliber [recent film Foxcatcher], it's not worth not being with my baby... Unless it's something spectacular, I really want to be a mother," Miller told the Evening Standard. "I have technically been on a break...I vowed to take the rest of the year off."

Sienna Miller Gives Birth To Baby Girl

Before the film break, Miller and her fiance' took the time to be photographed for Burberry's upcoming Autumn/Winter 2013 fashion campaign. In one of the black-and-white images the couple kisses passionately while holding each other in a warm embrace. In the second image, she is facing her fiancé and leaned into his body as his hand holds her bottom. The images were captured by famed fashion and celebrity lensman Mario Testino.

Burberry's Chief Creative Officer, Christopher Bailey, described the shoot as one "full of love and laughter."

"It was such a treat to work with Sienna and Tom, and to capture their magic together," he said in a statement.