See how the couple's relationship has progressed
The couple meet as on-screen lovebirds on That 70s Show, which airs from 1998-2006.
Despite their telly romance, Mila dates Macaulay Culkin for eight years until they end things in 2011 and Ashton weds Demi Moore in 2005.
The actor – who’s 16 years Demi’s junior – splits from his wife in November 2011.
In July 2012, it’s reported that Demi is convinced Mila and Ashton have been ‘hooking up for years’. Mila and Ashton insist they’ve always been just pals.
But the couple soon become more than just good friends and their romance is confirmed by September 2012, when they’re snapped enjoying a stroll in New York’s Central Park.
They don’t hide from photographers and are seen kissing, cuddling and feeding each other food as they munch on a bite to eat.
After being snapped with a rounder-looking tummy during a walk with Ashton in October 2012, Mila dismisses rumours that she’s pregnant.
The pair head to the UK in April 2013 while Mila films sci-fi movie Jupiter Ascending. They reportedly organise a romantic break to the Norfolk Broads.
Spotted wearing a huge diamond ring on her left hand in February 2014, speculation mounts that Mila’s engaged to Ashton.
She finally confirms her pregnancy and engagement on Ellen DeGeneres’s chat show in June 2014.
‘We were able to hide it for a very long time,’ she admits.
Five months later, Mila can’t help spilling about her long-term crush on her future husband.
‘My first real kiss ever was with him on the show,’ she reveals.
‘And when That 70s Show had a prom, my date for the prom turned out to be my fiancé. We can honestly say that we went to prom together!’
Keep reading to find out what else has happened to Mila and Ashton over the years…