Sienna Miller recently pushed maternity style boundaries as she showed off her bump in a Schiaparelli couture crop top and puff ball skirt at the Vogue World Show on Thursday.

The actress, 41, is expecting a baby with boyfriend Oli Green, 26, after debuting her bump on a beach visit in Ibiza in August. 

This will be Sienna's' second child - her first with Oli - after her daughter Marlow was born in July 2012. 

The father-to-be, however, is relatively private about his life, despite working in the public eye and dating film star Sienna. 

So, who is Oli Green, how did he and Sienna meet and who have they dated before one another? 

Sienna's boyfriend - 15 years her junior - is a fellow actor, as well as a model, who studied at at the Strasberg Theatre & Film Institute in New York.

According to IMDb, his first role of any sort was in the 2019 music video for John Eatherly's Burnout alongside Kaia Gerber when he was 22 years old.

Despite relatively few appearances on screen, Oli is building quite the contacts book, having appeared alongside Florence Pugh and Morgan Freeman in 2023's A Good Person, and Elizabeth Debicki, Imelda Staunton, and Dominic West, in an episode of The Crown the same year.

But Oli's modelling career took off first, and he has worked with many household names on promotions.

He was the face of Gap's 2017 I Am campaign, and has also appeared alongside Cara Delavigne in a string of Burberry jobs. 

From that world, Oli was previously linked with Adwoa Aboah and Paige Reifler.

While the exact date Sienna and Oli met is unknown, the pair began being romantically linked in early 2022 when they were spotted together in New York City.

Soon after, in March, their romance was confirmed when they left the BAFTAs together as they headed for British Vogue's Fashion & Film afterparty.

This was weeks before their red carpet debut as a couple, for the Vanity Fair Oscars party.

And that was far from their last  public appearance, with subsequent step-outs including at Wimbledon in July 2023. 

Sienna is currently pregnant with her second child, debuting her baby bump while on a beach in Ibiza.

This will be her first child with boyfriend Oli, while already a mother to daughter Marlowe, ten, with her ex Tom Sturridge, who is currently dating Alexa Chung. 

The news of Sienna's pregnancy comes after she revealed she froze her eggs after turning 40.

Speaking to Elle, Sienna told how she often wondered, 'should I have more [children], and why haven't I, and all of that, which is a really loud noise'.

She said: 'Biology is incredibly cruel on women in that decade – that's the headline, or it certainly was for me.

'Then I got to 40 and I froze some eggs. Having been really focused on the need to have another baby, I'm just like, if it happens, it happens. That kind of existential threat has dissipated.'

Speaking to The Sunday Times Style Magazine in 2019, Sienna told how she hoped to grow her family in the future.

She said: 'I would love to have more children. I would love it for my daughter as well. I think I would be open to getting married'.

Who have the pair previously dated? 

Due to Oli's private nature, it is unknown of who he has dated before Sienna, most especially any females from the industry.

The Layer Cake star is familiar with high-profile partners, with her first in 2004 when she and Jude Law became engaged, essentially elevating them as a celebrity power couple. 

Law was already a father then, and their relationship was strained by his admittance to having an affair in 2005 with the nanny of his then-three children, with the couple finally splitting in November 2006.

Sienna then became involved with another actor in 2008 - Balthazar Getty, who was married at the time.

In 2014, Sienna admitted to having a 'brief' affair with Bond actor Daniel Craig.

After rekindling with Law for just over a year, Sienna dated Tom Sturridge from 2011 to 2015, with whom she had her daughter Marlow. 

Her most recent relationship before Oli was art gallery owner Lucas Zwirner which was made public in January 2019.

Zwirner became Sienna's third fiancé, after Law and Sturridge, in January 2020 but their split was announced eight months later.