Emily Atack recently celebrated the birthday of Felicity Blunt, the executive producer of the Disney+ series "Rivals," with a gathering that included cast members from the show and actor Stanley Tucci.

Atack, who portrays Sarah Stratton in the series, documented the event on Instagram. The celebration for Blunt, who turned 45, saw attendees enjoying drinks and mingling in what appeared to be a barn setting. Among the co-stars present were Bella Maclean, Rufus Jones, Alex Hassell, Catriona Chandler, Lisa McGrillis, Gary Lamont, Hubert Burton, and Katherine Parkinson. Showrunner Dominic Treadwell-Collins and his husband Paul Sloss also attended.

Emily Atack let loose with her Rivals co-stars on Sunday as they enjoyed a boozy party to celebrate the birthday of the show's executive producer Felicity Blunt [pi9ctured with Bella Maclean]

Felicity Blunt, wife of Stanley Tucci, celebrated her birthday with friends and colleagues. Tucci was present at the festivities.

The party featured a cake made of cheese, which Blunt cut while holding a microphone, presumably to give a speech. Atack shared a birthday message for Blunt on Instagram, calling her "the most wonderfully astonishing woman."

Blunt served as an executive producer on "Rivals" and was also the literary agent for the late author Dame Jilly Cooper, whose 1988 novel inspired the series. Blunt represented Cooper for the final decade of her career.

"Rivals," set in the 1980s, follows the rivalry between TV executive Rupert Campbell-Black and media mogul Tony Baddingham over a television franchise. The series debuted on Disney+ in October 2024 and was renewed for a second season, which received positive reviews.

Birthday girl Felicity posing with Alistair and his son Barney

Atack's fiancé, Alistair Garner, and their son Barney were also in attendance, as was Atack's sister, Martha Atack.

Many of whom had a drink in hand, Emily's co-stars lapped up the atmosphere as they pulled off a number of fun poses before hitting the dancefloor [Katherine Parkinson and Lisa McGrillis]

Bella Maclean hit the dancefloor with Barney and her co-stars amid the fun birthday bash

Gary Lamont (Charles Fairburn) and Hubert Burton (Gerald Middleton) posed for a fun snap together

Other stars from the popular 80s-set 'bonkbuster' included Catriona Chandler (Caitlin O'Hara) and Lisa McGrillis (Valerie Jones) [both pictured]

Emily was certainly in high spirits as she mingled at the party snapping selfies with the likes of Bella Maclean (Taggie O'Hara), Rufus Jones (Paul Stratton) , Alex Hassell (Rupert Campbell-Black)

It was also a family affair for the former Inbetweeners star as she was also joined by fiancé Alistair Garner and their son Barney [Emily pictured with Alistair]

The actress' partner Alistair got up close and personal with show lead Alex Hassell (Rupert Campbell-Black)

Emily poses with onscreen husband Rufus Jones (Paul Stratton) and producer Dominic Treadwell-Collins

Dressed in a sparkly silver dress, Felicity looked radiant as she proceeded to cut her cheese cake. She also held onto a microphone presumably to make a speech to her guests