There have now been two Mamma Mia! films - and we are still no closer to finding out who the daddy is.
The entire plot of the first movie, based on the songs of ABBA and released in 2008, revolves around bride-to-be Sophie Sheridan trying to find out which man is her biological father.
She invites all three potential daddies, Irish-American architect Sam Carmichael, Swedish travel writer Bill Anderson and British banker Harry Bright, to her wedding to find out who should give her away.
And who wouldn't love the choice between Piers Brosnan, Stellan Skarsgard and Colin Firth?
In the end they all agree they do not want the paternity confirmed - and it's still a mystery at the end of the 2018 sequel Mamma Mia! Here We Go Again.
However, Amanda Seyfried, who plays Sophie in both movies, has pointed us in the direction of one possible father.
The Hollywood actress has shared her thoughts on which guy she is rooting for - and it could be a controversial choice.
Amanda secretly hopes that Skarsgard's character Bill is Sophie's dad because of their 'Voulez-Vous' scene.
"It's one of the purest moments in the movie because there’s a lot of pride in Stellan, but also a lot of shock and fear," she told Vanity Fair. "Just full acceptance in a small amount of time. It’s a full circle moment. It’s beautiful."
"Comedically he’s also very skilled, and because of this moment I always secretly hoped it was Stellan that was really her father. I'm sorry, Bill."
Amanda believes Bill seemed the least likely to want to have kids, which makes him an even better choice.
She continued: "From realization to acceptance, there is a scene that was cut of a song called 'Name of the Game,' and we sing it together, and I'm begging him, 'What's the name of the game?' We had a lot of fun. We got really tight."
Mamma Mia! fans will be hoping the daddy will finally be revealed in a third movie - and it seems likely one is on the way.
But there might be a long wait, as the sequel was released a decade after the original movie lit up the big screen.
Our favourite characters could be heading back to the Greek islands, as film makers have openly discussed making it a trilogy.
The producer of the first two Mamma Mia! films and stage show, Judy Craymer, discussed the potential of a third film being made, during an interview with the Daily Mail in 2020.
Craymer said she was planning to think about the third film throughout lockdown, but struggled to concentrate due to the effects of the coronavirus pandemic.
She said: "I was meant to have been getting on with that, in my head, during these months. But then I got hit with Covid fog. I think one day there will be another film, because there’s meant to be a trilogy, you see. I know Universal would like me to do it."
No official announcement about the proposed third film was made in the two years that followed, but director OI Parker had indicated it was planned to be a trilogy.
Parker, the writer and director of the second film, told Screen Rant: "Judy Craymer, the genius producer behind the musical and the first two films, always plans for it to be a trilogy.
"That's all I can say. The first one made an enormous amount of money, and I think we made a fair amount too. I know that there is a hunger for a third, and I know that she has a plan. Wouldn't it be lovely?"
While Lily James, who played the younger version of Donna in the sequel, is pushing for a third instalment in the franchise.
"I'm desperate for it to happen. It was like, it didn't feel real. It was so fun just singing on the beach and on a boat," she said last year. "I don't know. Why isn't it happening? We all need it. It's been COVID. It's been terrible. Let's do Mamma Mia.
"But only If I'm in it. They probably won't have me. It'll probably be like, Sophie's baby. Anyway! Let's stop talking about it."
