Emily Atack let loose with her Rivals co-stars on Sunday as they enjoyed a boozy party to celebrate executive producer Felicity Blunt’s birthday.The actress, 36, who plays Sarah Stratton in the hit Disney+ show, documented the merriment on Instagram, as Felicity, 45, celebrated alongside her colleagues and film star husband Stanley Tucci, 65.And Emily was in high spirits as she mingled at the party with the likes of Bella Maclean (Taggie O’Hara), Rufus Jones (Paul Stratton) and Alex Hassell (Rupert Campbell-Black).Other stars from the popular 80s-set ‘bonkbuster’ in attendance included Catriona Chandler (Caitlin O’Hara), Lisa McGrillis (Valerie Jones), Gary Lamont (Charles Fairburn), Hubert Burton (Gerald Middleton) and Katherine Parkinson (Lizzie Vereker), as well as show runner and executive producer Dominic Treadwell-Collins and his husband Paul Sloss.Emily was also joined by fiance Alistair Garner and their son Barney, as well as her agent sister Martha Atack. Set in an idyllic barn, the drinks were flowing as Felicity’s friends and loved ones gathered to celebrate in style. Emily Atack let loose with her Rivals co-stars on Sunday as they enjoyed a boozy party to celebrate executive producer Felicity Blunt’s birthday (pictured with Bella Maclean) Emily delightedly documented the merriment, as Felicity, 45, celebrated alongside her colleagues and film star husband Stanley Tucci, 65 (pictured)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.Emily took time to film everyone singing happy birthday to Felicity as she blew out her candles on a cake made from cheese, with her Devil Wears Prada star husband stood proudly by her side.Captioning her post, Emily penned: ‘The most beautiful day for THEE most wonderfully astonishing woman that is Felicity Blunt – you are so loved and you spoil us all beyond belief with your kindness and constant insistence on everyone having the best time ever HAPPY BIRTHDAY WE LOVE YOU!’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. Felicity serves as one of the executive producers and was also the literary agent for the late Rivals author Dame Jilly Cooper.Felicity represented the late Jilly for the last decade of her career, which was undoubtedly a big honour for her as a longtime fan of the author. Sharing her love for Jilly’s work in a recent interview with Tatler, Felicity gushed: ‘I was a die-hard obsessive, I read all of the manuscripts as soon as they came in and could quote swathes of text… it was like my Mastermind subject.’She is undoubtedly a large part of why I ended up a literary agent.’ 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, pictured) Other stars from the popular 80s-set ‘bonkbuster’ included Catriona Chandler (Caitlin O’Hara, right) and Lisa McGrillis (Valerie Jones, right) Gary Lamont (Charles Fairburn) and Hubert Burton (Gerald Middleton) posed for a fun snap together 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) Emily poses with onscreen husband Rufus Jones (Paul Stratton, left) and producer Dominic Treadwell-Collins, middle The actress’ partner Alistair, left, got up close and personal with show lead 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) Birthday girl Felicity posing with Alistair and his son Barney Bella Maclean hit the dancefloor with Barney and her co-stars amid the fun birthday bash 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 Captioning her post, Emily penned: ‘The most beautiful day for THEE most wonderfully astonishing woman that is @felicityblunt – you are so loved and you spoil us all beyond belief’The pair had a very close relationship, with Jilly and Felicity communicating in some form or another on a daily basis. Following Jilly’s sudden death in October aged 88, Felicity was understandably devastated, with the agent adding to the publication: ‘I feel so sad, I’m bereft. Everyday was a squeeze for all it was worth, but it was just too soon and she was having so much fun.’Based on Dame Jilly’s 1988 novel, comedy-drama Rivals debuted on Disney+ in October 2024 and immediately became a huge hit. The eight-episode first series ended in October 2024 and was soon renewed for a second outing. Ahead of its release on May 15, Rivals series two received rave reviews from critics, who hailed it an ‘exquisite bonkbuster’ that was able to live up to the acclaimed first season.The official synopsis for Rivals reads: ‘In the cutthroat world of 1980s television, where the shoulder pads are big and ambitions even bigger, a long-standing rivalry boils over.’In this award-winning drama capturing the joy, excess, and brazen power-grabbing of the affluent elite in 1980s England, ex-Olympian and notorious womaniser Rupert Campbell-Black goes head-to-head with the media mogul Tony Baddingham in a bid to win the Central South West television franchise.’Amidst the hedonistic glamour of ’80s excess, the personal lives of our Rutshire heroes spiral into chaos when illicit affairs threaten to shatter families, and long-buried secrets ignite with explosive consequences.’As rivalries push everyone to the brink, loyalties are tested and hearts are broken in the pursuit of victory. But what is the true cost of war?’