How friendly exes Sienna Miller and Tom Sturridge are redefining the modern family as actress's former flame gets engaged to her best friend Alexa Chung

Forget bitter breakups and awkward encounters, Sienna Miller and Tom Sturridge are redefining what it means to be a modern family. Instead of the typical Hollywood drama, the British 'It' girl and the Sandman actor have mastered healthy blended family dynamics. Tom, 40, and Sienna, 44, split in 2015 and have remained close, with both dedicated to raising their daughter Marlowe, now 14.So amicable are the pair, that there has been no blowback to Tom moving on with Sienna's best friend Alexa Chung, with the couple confirming their engagement this week. Meanwhile, Sienna is engaged to actor Oli Green, 29. Proving that they are the friendliest of exes, both couples were seen together at Wimbledon in 2022, where they were pictured kissing their respective new partners. Rather than an awkward encounter, the four were also seen taking a group selfie in the stands. How friendly exes Sienna Miller and Tom Sturridge have become the ultimate poster for a modern family Instead of the typical Hollywood drama, the British 'It' girl and the Sandman actor have mastered healthy blended family dynamics (Tom pictured kissing Alexa Chung with Sienna sitting in front) Sienna went on to date and become engaged to actor Oli Green, 29. Meanwhile, Tom is set to marry Alexa, with their engagement confirmed earlier this weekIn a 2023 Vogue interview, Sienna described dinners with Tom, Alexa, Oli and Marlowe as 'very loving and cozy and great', adding: 'It's ideal. It's incredible. We are very lucky.' Tom and Sienna were together from 2011 to 2015. They got engaged and had a daughter before separating three years later.Post-split, they remained good friends, frequently walking dogs together and living in close proximity to raise their daughter.At the time, it was claimed the pair had different goals. A source said: 'Tom wanted to get married and have more children. Sienna didn't.'Following their split, Sienna gushed to Harper's Bazaar that Tom was her 'best friend in the entire world' – and that while they don't share a property, they often stay together to spend time with their little girl.Admitting their close bond has not broken since they cut romantic ties in the summer of 2015 after four years together, she explained: ‘We still love each other.'I think in a break-up somebody has to be a little bit cruel in order for it to be traditional, but it’s not been acrimonious in a way where you would choose to not be around that person.'Of co-parenting, in 2019 she told Elle UK: 'It's not like there's a structure for custody. We make it work. It's not conventional.' Following their split in 2015, Sienna gushed to Harper's Bazaar that Tom was her 'best friend in the entire world' (pictured in 2014) Sienna began dating her now fiancé Oli after meeting at a mutual friend's Halloween party in 2021 The following year, Tom confirmed his romance with Alexa at a Vanity Fair partySienna went on to date Lucas Zwirner, whom she became engaged to in 2020, but they called off their relationship a year later.She then had a brief romance with business leader Archie Keswick, while Tom had romances with Georgina Huddart and Maya Hawke.Sienna once recalled how she was living with her ex and Tom, as well as his then girlfriend in Upstate New York during the pandemic so they could co-parent.She told the fashion bible: 'I had my then boyfriend,' said Sienna, pulling a face that suggests he is not, and never will be, held in the same esteem as Tom.'And Tom's then girlfriend came and... it was definitely eccentric,' she said, laughing, putting her face in her hands. 'I can't go into detail but the wheels came off and everything went horribly wrong... It will make a fantastic play.' Then in 2021, Sienna began dating her now fiancé Oli after meeting at a mutual friend's Halloween party. The following year, Tom confirmed his romance with Alexa at a Vanity Fair party.Speaking in the December edition of Vogue UK, Sienna expressed her approval for the romance, and said: 'I'm really happy for them. It's genuinely lovely.'She even joked about their co-parenting situation and revealed that Marlowe has come home with Alexa's jumpers which she has since claimed for herself.Sienna quipped: 'I've got one upstairs!'In 2023, Sienna opened up further about her daughter Marlowe's relationship with Tom and Alexa. Sienna admitted that Marlowe thinks supermodel Alexa is 'much more fashionable' than her, despite both being iconic British style inspirations.In an interview with Vogue, Sienna was asked whether her daughter realises that between her mother and Alexa she has access to two of the greatest wardrobes.Laughing, Sienna replied: 'We tell her, she's never going to give me that. I think she’s starting to cotton on and I have an aesthetic and maybe it was appreciated, but she’s still like no no.'Talking specifically about Marlowe's relationship with Alexa, she continued: 'Alexa she is much more generous to because she is exquisitely dressed and not her actual mother.'In February 2025, Sienna was photographed with Alexa at a dinner celebrating her Barbour clothing collection at Tollington's Fish Bar in north London, with both Tom and Oli also among the guests.Last month, Sienna also referred to Alexa as her daughter's 'stepmum' in an interview with The Observer, praising her social media skills. Speaking in the December edition of Vogue UK, Sienna expressed her approval for the romance, and said: 'I'm really happy for them. It's genuinely lovely.'Meanwhile, Alexa and Tom have made occasional high-profile appearances together, including at the Met Gala in New York in May this year. Earlier this week, Alexa confirmed her engagement to Tom – and he proposed with a 'haunted' Tudor ring.The model and TV presenter revealed they are planning to tie the knot after four years together.It is Alexa's first public confirmation of the engagement, which was initially rumoured in June 2023 when she was spotted with a ring on her left hand at fashion designer Henry Holland's 40th birthday celebrations.Speculation grew in 2024 after she was photographed wearing a ring during Paris Fashion Week.That year, reports claimed the couple were engaged and hoping to hold an intimate wedding, although neither publicly announced any plans at the time.Alexa – who shot to fame co-hosting Channel 4's music and pop-culture show Popworld – previously appeared unconvinced by the idea of marriage.In a 2018 interview with Porter magazine, she said: 'I just don't get why marriage is different from non-marriage,' adding that she did not need 'a wedding day per se'.