Black tie: Justin Bieber, 27, and his wife Hailey, 24, were both dressed to the nines in all-black ensembles for a party in West Hollywood celebrating his art gallery auction

Justin opted for a slim black bowtie with his tux, which featured notched lapels.

He still sported a close-cropped hairdo after shearing his shaggy locks (which he briefly styled into controversial dreads) earlier this summer.

He and Hailey were unusually close, as if he was supporting her as they stepped out of the venue.

He kept one arm wrapped behind her back and another hovering over her hip and midriff.

Classic: Justin opted for a slim black bowtie with his Saint Laurent tux, which featured notched lapels

Short hair, don’t care: He still sported a close-cropped hairdo after shearing his shaggy locks (which he briefly styled into controversial dreads) earlier this summer

It takes two: He and Hailey were unusually close, as if he was supporting her as they stepped out of the venue. He kept one arm wrapped behind her back and another hovering over her hip and midriff

End of the evening: Hailey looked stone-faced and had her face pointed toward the ground as her husband escorted her

Hailey looked stone-faced and had her face pointed toward the ground as her husband escorted her.

Their serious faces were a far cry from photos Hailey shared on Instagram earlier in the evening that showed them smiling playfully at each other while Justin drank from a red plastic cup.

The daughter of Stephen Baldwin put on a busty display in the low-cut dress.

The long-sleeve ensemble featured puffy sleeves and had an intriguing see-through skirt that reached to the ground.

Revealing: The daughter of Stephen Baldwin put on a busty display in the low-cut dress

Peekaboo: The long-sleeve ensemble featured puffy sleeves and had an intriguing see-through skirt that reached to the ground

Putting on a show: The front and back panels were black and opaque, while the sides were made of sheer fabric and black lace and showcased her toned legs

The front and back panels were black and opaque, while the sides were made of sheer fabric and black lace and showcased her toned legs.

Hailey matched her dress with a set of pointy black heels and accessorized with long dangling Tiffany & Co. diamond earrings.

She had her blond tresses tied back tightly and wrapped into a high bun, with one thick strand dangling free by her face.

In her more cheerful Instagram photos from earlier that evening, she rested her hand on Justin while calling her husband her ‘LOML,’ or ‘love of my life.’

Standing tall: Hailey matched her dress with a set of pointy black heels and accessorized with long dangling Tiffany & Co. diamond earrings

Tied up: She had her blond tresses tied back tightly and wrapped into a high bun, with one thick strand dangling free by her face

Their serious faces were a far cry from photos Hailey shared on Instagram earlier in the evening that showed them smiling playfully at each other while Justin drank from a red plastic cup

‘LOML’: In her more cheerful Instagram photos from earlier that evening, she rested her hand on Justin while calling her husband her ‘LOML,’ or ‘love of my life’

Among the high-profile guests at the party were the R&B singers Kehlani and Usher.

Kehlani, 26, arrived at the event with a female friend whom she held hands with while clutching her phone in her other hand.

She wore a a white shirt that was enlivened with a lustrous stripe of silver material along the strip of buttons that dangled past the shirts hem.

She covered up her top with a short black vest and had on baggy black trousers.