Kristen Stewart's girlfriend Stella Maxwell playfully smooches mystery man at fashion party

She's in a relationship with Kristen Stewart.

Yet Stella Maxwell showed off her flirty side at the 7 For All Mankind clothing launch, as she shared a smooch with a mystery man.   

At the official launch of the new campaign at the Beverly Hills Hotel in Los Angeles on Tuesday, the New Zealander, 28, flirted her way through the night with a male companion. 

Stella has been dating Kristen since 2016, and was previously linked to Miley Cyrus.

Meanwhile, Kristen has past been in high-profile romances with singer St. Vincent and actor Robert Pattinson.

Yet Stella was not accompanied by her girlfriend for the party, where she slipped her slender frame into a plain white cropped T-shirt for the occasion, flashing a hint of her toned stomach.

Stella edged-up her look with black, high-waisted patent leather jeans which clung to her slim pins as she posed for photographs.

The blonde beauty teamed her monochrome ensemble with coordinating biker boots featuring stud-embellished heels.

The Victoria's Secrets Angel accessorised with an array of silver rings and bracelets, a chain necklace as statement earrings.

Stella looked impossibly beautiful with a subtle smokey eye, flawless pale skin and a bold fuchsia pink pout.

For her big night, she styled her blonde tresses into loose beachy waves which cascaded down her shoulders.

At one point, after cosying up to milliner Nick Fouquet for a photograph, Stella borrowed his leather-trimmed tan coloured cowboy hat to pose with.

But by far, the model's flirtiest display was with a mystery man, who she was sat next to during the lavish dinner.

In footage shared on Instagram by her friends, Stella can be seen putting her hands around the handsome hunk and playfully pulling him in for multiple kisses.

Along with her mystery man, the stunning model was joined by a host of American socialites, models and fashion industry insiders.

She playfully pouted for snaps with artist and model Langley Fox Hemingway, 29, who is the great-granddaughter of American author Ernest Hemingway.

The brunette beauty flaunted her slim pins in a leather mini skirt and biker boots, which she teamed with a white crop and black blouse.

Langley carried her belongings in a stylish red bumbag slung across her body, keeping her hands free to lark about with Stella.   

Model and stylist Djuna Bel (who is best friends with Harry Styles’ model ex-girlfriend Camille Rowe) kept things simple in a plain black cap-sleeved tee.

The leggy beauty kept her ensemble muted as she teamed her top with an indigo denim skirt and Chelsea boots.

The blonde-haired fashionista followed Stella's lead, opting for a bold red lip to add a touch of glamour to her look.

She flaunted her slim frame with a black waist belt, and added subtle kinks to her endless blonde locks.

The blonde stylist and brunette artist posed together, and appeared to be in good spirits, giggling and laughing at the event in honour of their friend Stella fronting the clothing brand's new collection. 

American actress Christa B. Allen, 26, was also in attendance, commanding attention in a striking, sheer animal print gown.

She posed confidently for photographs, flaunting her enviable figure in the floor-length dress, which allowed her high-waisted briefs and black bra to be seen.

Before guests arrived at the glamorous event, Stella posed solo amongst the collection of clothes which she is fronting.

Sitting and even lying across a table of jeans, Kristen Stewart's girlfriend showed off her best modelling moves.

Stella proudly positioned herself in front of a pull-up banner displaying a photograph of herself wearing pieces from the new collection.

She seductively lounged on a cyan blue couch, teasing the camera provocatively with winks and pouts.

The model seemed delighted with the campaign brochure, filled with images of her wearing clothing from the collection.  

After her sumptuous launch party at the five-star hotel, Stella headed to Peppermint nightclub in West Hollywood to attend a Jesse Jo Stark concert and continue on with her celebrations.

Stella first made her mark in the fashion industry as a Victoria's Secret angel.

Now, she is featured alongside actor Ashton Sanders, body activist Paloma Elsesser and others for the new 'We Are Mankind' clothing campaign.

Stella and Kristen Stewart have been romantically linked since 2016, when Stella visited the Twilight actress on the set of her upcoming movie Lizzie in Savannah, Georgia.