They went public with their romance last week when they were seen sharing a passionate PDA at Heathrow Airport.
And it seems Cara Delevingne's relationship with actress Ashley Benson, 28, is going from strength-to-strength, as the model, 26, has introduced her new girlfriend to her big sisters Poppy, 32, and Chloe, 33.
The Suicide Squad star amassed a group of family and friends to attend a Secret Cinema screening of Baz Luhrmann's 1996 classic Romeo + Juliet, starring Claire Danes and Leonardo DiCaprio, in Acton, west London on Saturday night.
Dressing as opposing members of the warring Montague and Capulet families, Poppy posted a series of snaps on her Instagram page of the group in full fancy dress.
As well as Ashley and the three Delevingne sisters, the gang also included Poppy's husband James Cook, socialite Lady Mary Charteris, supermodel Adwoa Aboah, and a group of other friends.
Poppy followed suit in her own striking shirt and jean combo - while the stunning siblings both showed off their model prowess with their signature pouts.
Sister sister: The Suicide Squad star (fourth left next to Poppy) amassed family and friends to attend a screening of Romeo + Juliet in Acton, west London (Ashley and Chloe far right)
Squad goals: Ashley and Chloe posed alongside socialite Lady Mary Charteris (left) and supermodel Adwoa Aboah (second left) at the cinematic event
Ashley wasn't too far away, as the Los Angeles-based actress posed as part of another team, and threw her own sultry pout while dressed in an edgy leather jacket and red mini skirt.
Poppy kept quiet about her sister's new romance during the evening, mentioning neither Cara nor Ashley in her caption, but did tag the stars in her dramatic snaps.
The Kingsman star wrote: 'In fair Verona where we lay our scene... Team MONTAGUE vs Team CAPULET. Thank you @secretcinema for bringing this magical movie to life...
'For never was a story of more woe than this of Juliet & her Romeo” P.S CIGS & CUTS are fake peopleeee.'
New love: The family introduction comes just days after Cara and Ashley were spotted passionately kissing at Heathrow Airport on Tuesday, confirming their new romance
The family introduction comes just days after Cara and Ashley were spotted passionately kissing at Heathrow Airport on Tuesday, in confirmation of their new romance.
The pair looked besotted with each other as they queued up for a taxi outside the terminal, with Cara wrapping an affectionate arm around the actress.
Smiling widely as they chatted, the couple were then seen indulging in a number of passionate kisses as they waited for their ride into central London.
Seemingly proving their close relationship further, Ashley even sported a delicate gold 'C' pendant around her neck, in apparent tribute to her new love.
MailOnline has contacted representatives of both Cara and Ashley for further comment.
Ashley and Cara had been working together on their upcoming movie Her Smell at the time, which is believed to be released in 2019.
Cara has previously dated the likes of model and actress Paris Jackson, 20, singer St Vincent, 35, and Fast And Furious star Michelle Rodriguez, 40.
Loved up: Seemingly proving their close relationship further, Ashley even sported a delicate gold 'C' pendant around her neck, in apparent tribute to her new love
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