By EMANUEL RAMIREZ and LILLIAN GISSEN, US DEPUTY FEMAIL EDITOR
Brooks Nader was spotted cozying up to a mystery man in Las Vegas weeks after rumors erupted that she was involved in a 'love triangle' with tennis titans Jannik Sinner and Carlos Alcaraz.
The model, 28, partied the night away during GRAND Reveal Weekend at Marquee Nightclub inside the Cosmopolitan of Las Vegas hotel on Saturday night.
She sizzled in a figure-hugging black jumpsuit, which had an extremely low-cut neckline, leaving her ample cleavage on full display.
She paired the look with some dark shades and nude pumps, and left her blonde locks in loose waves.
But the star had a slightly awkward moment at one point when she endured an accidental wardrobe malfunction.
While filming a video of herself dancing, Brooks spilled out of her busty top, with her nipples flashing the camera.
The 28-year-old was joined by her sisters Mary Holland Nader, Sarah Jane Nader, and Grace Ann Nader, who looked equally as glamorous.
Mary Holland, 26, opted for a tiny white dress, while Sarah Jane, 22, wowed in a sparkling gold number.
Brooks Nader partied the night away during GRAND Reveal Weekend at Marquee Nightclub inside the Cosmopolitan of Las Vegas hotel on Saturday night
She was spotted cozying up to a mystery man in Las Vegas weeks after rumors erupted that she was involved in a 'love triangle' with tennis titans Jannik Sinner and Carlos Alcaraz
Grace Ann, 25, for her part, wore a mini skirt and matching bra set, which she paired with a leather jacket and cowboy boots.
The sisters set fire to Vegas nightlife, dancing and sipping cocktails until the wee hours of the morning.
Elsewhere during the evening, Brooks was seen getting flirty with an unknown male companion.
An onlooker exclusively told the Daily Mail that the man 'beelined' over to Brooks in the VIP section of the club.
'I saw him walk up to VIP and go straight over to her. Beelined it to her and had a hug and chat,' they said.
Exclusive video footage shows Brooks embracing the mystery man as he leaned in and whispered in her ear.
The two chatted for a moment and Brooks smiled warmly at him, before they parted ways.
While reports recently showed that tourism in Las Vegas drastically declined this summer, it didn't seem to effect the celebration at Marquee on Saturday.
Exclusive video footage shows Brooks embracing the mystery man as he leaned in and whispered in her ear. The two chatted for a moment and Brooks smiled warmly at him
Brooks had a slightly awkward moment at one point when she endured an accidental wardrobe malfunction
While filming a video of herself dancing, Brooks spilled out of her busty top, with her nipples flashing the camera
Read More Tennis's superstar love triangle: Carlos Alcaraz and Jannik Sinner 'dating the same swimsuit model'
In addition to the celebrity appearances like Brooks and her sisters, roughly 4,000 people turned up to celebrate.
It felt like a revival of Vegas and the return of the 2000's club life following the news that Las Vegas recorded only 4.56 million passengers for August - an almost six percent drop compared to the same month last year.
Brooks' outing comes weeks after reports emerged that said the social media star was dating both Sinner and Alcaraz against the backdrop of the US Open.
Nader's sister Grace Ann first sparked speculation that Brooks and Sinner were romantically entangled in August when she said her sibling was involved with someone 'whose name rhymes with winner.'
The model shut down suggestions that she was dating Sinner, however, on Jimmy Kimmel's famous late-night talk show, hinting that she was dating a different tennis pro instead.
Soon after, Grace Ann claimed at an event that Nader was dating Alcaraz, stating that the 'rumors were true' and he was 'the man of the hour.'
In a turn of events reminiscent of the movie Challengers, reports emerged soon after that Nader was dating both Alcaraz and Sinner at the same time - who were set to face off in the men's US Open finals.
Brooks sizzled in a figure-hugging black jumpsuit, which had an extremely low-cut neckline, leaving her ample cleavage on full display
She was joined by her sisters Mary Holland Nader, Sarah Jane Nader, and Grace Ann Nader, who looked equally as glamorous
However, journalist Alberto Guzman - citing information from Alcaraz's inner circle - said on Spanish TV show No Somos Nadie that Brooks was not dating the Spanish star.
'They're not dating, it's not an official relationship,' he said. '[Alcaraz] confirmed to those close to him that he is single and has no intention of having any serious relationships. Perhaps she is not well informed.'
Even so, Brooks added to the speculation with comments she made on late-night television show Watch What Happens Live weeks later.
When asked about the Challengers-esque dating set-up by host Andy Cohen, Brooks seemed deliberately vague.
'I would just say, a lady never kisses and tells - especially twice, that's just not nice,' she said.
'Dating is such a loose term these days. It's just... I don't know. By the way, my only thing is, guys do it all the time, so why can't I do it?'