It has been revealed she has been secretly dating New Zealand–born actor Martin Henderson.
And it appears Demi has a thing for the younger man as Martin is 12 years her junior.
The pair were spotted enjoying a romantic getaway in Connecticut last week in pictures obtained by US magazine Life & Style.
Demi and Martin headed out for a spot of lunch at Nine Main Bakery and Deli in New Preston before going grocery shopping on their way back to the house where they were staying together.
The eagle-eyed among you may recognise Martin, who is a TV star in Australia, from Britney Spears' Toxic video in 2004.
"She is beyond heartbroken. Even though Ashton cheated on her all the time, it was with random girls, it wasn't a relationship like it is with Mila and that is what is killing Demi now."
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> IN PICS: AGE-GAP COUPLES
Brad Pitt and Angelina Jolie - 12 years
It's easy to forget that there's quite a big gap in age between Brad and Ange, probably because he looks so much younger than his 46 years
Madonna and Jesus Luz - 28 years
The 10-year age gap with Guy Richie obviously wasn't enough for Madge, because her next flame was just 23 years old - while she was aged 51. It seemed like a fling at first, but they lasted a fair old while before splitting up in early 2010
Mariah Carey and Nick Cannon - 10 years
There's a decade in age between Mariah Carey and her hubby Nick Cannon, she's 39 and he's 29 - but that's not much of a gap at all by modern celeb standards
Michael Douglas and Catherine Zeta Jones - 25 years
Quarter of a century is a fair old age gap in anybody's book, but Mickey and Cath seem happy enough together - and she was comfortable enough with the reputation that their marriage earned her to mock it in Intolerable Cruelty
Rod Stewart and Penny Lancaster - 26 years
For years Rod was known as the oldest swinger in town, but Penny has firmly tamed his roving ways and he seems devoted to her
Ronnie Wood and Ekaterina Ivanova - 42 years
But just to prove that age-gap relationships don't always work out well, Ronnie Wood famously left wife Jo for Ekaterina Ivanova - who is a whopping 42 years his junior. They've long-since broken up, which left Ekaterina free to enter the Celebrity Big Brother house and flirt with Basshunter
Sam Taylor-Wood and Aaron Johnson - 23 years
Sam and Aaron are more than 20 years apart, but they haven't let the hefty age gap stop them getting engaged and conceiving a child together
Stephen Fry and Steven Webb - 27 years
Stephen Fry had just split up with his partner of 14 years Daniel Cohen when he apparently began consoling himself in the arms of a much younger beau. His rumoured love interest was 25-year-old Steven Webb
Tom Cruise and Katie Holmes - 16 years
Plenty of people have been cynical about TomKat's marriage, but we're not goiong to cast any aspersions. Our lawyers wouldn't let us anyway, but they seem happy enough together