While you would think working with an ex wouldn't be an ideal situation, for ABBA it has been the best thing for their "bond."
The 'Dancing Queen' hitmakers surprised fans last April, when they announced they would be recording new music for the first time since in 37 years - and it seems they are now closer than ever before.
Speaking to The Sun newspaper, Björn Ulvaeus says seeing his bandmates - Agnetha Fältskog, Benny Andersson and Anni-Frid Lyngstad - at work again has "strengthened and solidified" their relationships.
"Coming together like that, for me at least, strengthens and solidifies and confirms our bond," he said.
"And especially when the ladies went into the studio and stood by their mics and started singing, then, oh, it's that sound - the quality of the two ladies when they sing."
The band - who split in 1982 - are set to release their new tracks, 'I Still Have Faith In You' and 'Don’t Shut Me Down' – in 2020.
Before they went their separate ways Björn, 74, divorced bandmate Agnetha, 69, whilst Benny, 72, and Frida, 73, split up, too.
Björn called the reunion proof of "two former married couples getting along very well."
However, he insisted that he still believes they would have disbanded whether they were still in couples or not.
He said: "We could never have just gone on with ABBA having one hit every five years or so. No! It was never in the cards."