It used to be 'their thing'.
But now Madonna has dumped her former party co-host Demi Moore in favour of her friend's younger ex-husband Ashton Kutcher.
It seems Madonna is on team Ashton, after the Jobs actor and not his former wife attended Madonna's annual post-Oscar party.
Ashton was spotted partying the night away at the event held in a private home on Sunday, but Demi was noticeably absent.
Demi had co-hosted the event with the pop star in 2011 - she was unable to do the same in 2012 as the 50-year-old was in rehab post her split with Ashton - but this time the Charlie's Angles star was not even in attendance, let alone hosting.
And, according to Radaronline, this was no accident.
A source told the website: 'Madonna is firmly on side Ashton. She adores him and thinks that out of him and Demi he’s the one with the glittering career.
'Also, Madonna loves having Ashton around as he’s great eye candy, he’s funny and he flirts outrageously with her - in Madonna’s eyes, there’s no competition - when it comes to picking sides Ashton is the obvious winner.'
Held at Madonna's manager Guy Oseary‘s mansion, the celebrity studded crowd was even shocked when Ashton, and not Demi, arrived.
'When Ashton walked in it got the crowd buzzing,' a party-goer said.
'Madonna’s never spoken about the split, but it’s obvious she’s sided with him over Demi.
'It was kind of shocking as Demi has even hosted the party with Madonna in the past, so it’s even more of a mega snub.
'Madonna clearly loves Ashton though, they were dancing together a lot throughout the night and flirting up a storm.'
Also enjoying the night was John Travolta, Bradley Cooper, Daniel Day Lewis, Channing Tatum, Anne Hathaway, Ryan Gosling and Eva Mendes.
As well as Hollywood heavyweights Jack Nicholson, Salma Hayek, George Clooney and Leonardo Dicaprio.
Ashton finally filed for divorce from Demi in December, over a year since the couple split.
The pair were married six years but in the documents the Two and a Half Men star cited irreconcilable differences as the reason behind the split.