Selena Gomez and Gigi Hadid among the stars sharing behind-the-scenes photos... as they get ready for Taylor and Travis' wedding celebrations

Some of 's closest friends are letting fans in on the behind-the-scenes as they get all glammed up for her big wedding celebration weekend.

Swift is said to be throwing multiple celebrations this weekend in honor of her tying the knot with , and of course, many of their loved ones are by their side. 

There are conflicting reports about whether Swift and Kelce have already gotten married, but there are plans for an enormous party with 1,000 guests in on Friday night.

On Thursday night, some of her closest friends gathered at the Infosys Theater at Madison Square Garden for an intimate kickoff celebration.

Famous attendees included , Jack Antonoff, and , as well as the singer's childhood friend Abigail Anderson, the total count rumored to be capped at 100.

And while some A-list attendees have appeared to stay mum around the event and what they're wearing, others have taken to Instagram to share sneak peeks of their stunning looks.

On Friday, Selena Gomez's stylist, Erin Walsh, posted the pop star's look from night one of the celebrations. 

Gomez wore a stunning, strapless black floral lace gown by Oscar de la Renta, complete with a pair of heels from Jimmy Choo.

The dress also appeared to have a sexy slit up the thigh.   

She wore her hair in a slick-back updo, which showed off her dangling diamond earrings and a diamond ring made by Fernando Jorge, the pieces reportedly totaling $40,000.

Gomez also teased her in a car on her way to Thursday night's celebrations, using the special moment to promote a lipstick from her Rare Beauty brand.

The clip showed her applying the pink lipstick in the back of a car while wearing a glamorous black gown. She then shared a close-up photo showcasing the lip product, a forthcoming release from her brand.

look for Thursday night's festivities.  

Hadid's hairdresser, Dimitris Giannetos, shared new photos on Instagram of the recent cut and style he had done for the star. 

The pictures showed Hadid sporting gorgeous, bouncy layers that framed her face, the length hitting just below her shoulders.

Hadid was snapped showing off her new hair while wearing a blue t-shirt, glowing makeup, and a stunning mauve lip color.

Her golden locks looked voluminous, as Giannetos called the style 'love layers.'

'I wanted to create the updated version of the C-cut this evening [giving] Gigi some Love Layers (aka heart shape layers)!' he wrote in the caption.

'A bit more lift on the roots and the first layers start hitting a little below the chin 'till the tips of the hair! It creates basically an illusion of heart shape layers! Volume on the top and more narrow at the bottom!'

'In this case you can create an illusion of contour with the haircut so the face looks more structure! Always this haircut looks good w a mid part!' he added.

He also shared insight into how he perfected the look, detailing that he used a round brush to achieve the shape.

'A big round brush, pin the hair up 'till they cool down after, brush the hair with your fingers and lastly, spray some hairspray 'till you create your heart shape layers, your love layers!' he explained.

Olympic gymnast Simone Biles also shared a peek into her getting-ready process, as she took to Instagram on Friday afternoon to reveal the glam set up at her hotel.

She posted a table with tons of makeup products on it, which included powders from Huda Beauty and Makeup by Mario.

The star, who is married to NFL player Jonathan Owens, also tagged hairstylist Justin Revenge and makeup artist Deja Blackwell in the snap. 

Festivities are set to kick off again on Friday evening, as the couple is expected to welcome 1,000 guests at MSG. 

Swift and Kelce reportedly confiscated their guests' phones to avoid leaks at the party on Thursday, and NYPD officers will be working the event all weekend. 

Guests are expected to arrive at MSG at 3.30pm ET, and the festivities will kick off around 5pm. City permits suggest the extravaganza could go on until 4am.