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This is what you wear to the club too, right?

Mariah Carey looked a tad, uh, underdressed when she hit the red carpet at 1Oak nightclub at the Mirage hotel and casino in Las Vegas the evening of June 25.

The diva showed up in black lingerie -- complete with fishnet stockings, a garter belt and Christian Louboutin's $945 black leather Marlenarock stilletto heels -- topped with a cropped leather jacket.

Mimi was also -- duh -- dripping in diamonds, including her 35-carat engagement ring from her Australian billionaire fiance, James Packer.

The 47-year-old diva headed to 1Oak after performing in her "#1 to Infinity" residency show at The Colosseum at Caesars Palace to host a DJ set that, for the first half hour, featured only her own music.

Once inside, Mariah hung out in a VIP area sipping Dom Perignon, of course, then slipped into the DJ booth where she at one point sang along to her hit "It's Like That" and told the crowd, "I love you, darlings," 1Oak shared on its website.

Although her fiance was not with her, he was there in spirit: 1Oak waitresses carried giant photos of Mariah and James' heads around with them inside the club.

After an hour of holding court, Mariah -- in all her corseted glory -- left the hotspot.

Her scantily clad outing comes just days after estranged husband Nick Cannon seemingly finally agreed to sign divorce papers after more than a year of stalling following their 2014 split.

On June 16, Nick shared a four-minute rap called "Divorce Papers" on SoundCloud and his social media accounts in which he talked about his headline-making split from the pop icon.

He got straight to the point and got pretty personal in his emotional freestyle rap, when he flat out says, "F--- it, I'll sign these papers."