The movie marks the directorial debut of Bradley Cooper, 43, who also co-stars in the film.

The in-demand acting duo have been regulars on the red carpet since its debut at the Venice Film Festival in August.

At a screening of their new flick last night, the blonde star who is no stranger to outlandish outfits, suffered an unfortunate wardrobe malfunction.

Wearing dark sunglasses, the award-winning singer donned a 𝑠e𝑥y leather coat dress with thigh-high boots.

A matching leather belt nipped the dress in at the waist and highlighted the hit-maker’s slim frame.

Lady Gaga dons leather dress for A Star Is Born screening (Image: Splash)

Lady Gaga wore a 𝑠e𝑥y leather dress for A Star Is Born screening last night (Image: Splash)

However, the daring split revealed a little more than intended as she walked to the car.

Lady Gaga’s dress slipped open to reveal her underwear underneath.

The singer-turned-actress appeared oblivious to the wardrobe malfunction as she left the event with her fiancé Hollywood agent Christian Carino, 49.

The couple held hands as they made their way through the crowd of waiting fans outside the screening.

Lady Gaga’s dress slipped open to reveal her underwear underneath (Image: Splash)

The award-winning singer donned a 𝑠e𝑥y leather coat dress with thigh-high boots (Image: Splash)

Lady Gaga left the event with her fiancé Christian Carino (Image: Splash)

Lady Gaga suffered an embarrassing wardrobe malfunction at the screening of A Star in Born (Image: Splash)

The couple held hands as they made their way through the crowd (Image: Splash)

Lady Gaga stepped out in London last night for a screening of her new movie (Image: Splash)

A huge crowd of fans were waiting outside the screening (Image: Splash)

The movie marks the directorial debut of Bradley Cooper who also co-stars in the film (Image: Splash)