A Mamma Mia! theory may finally answer the long-standing question of who Sophie’s real dad is. Mamma Mia!’s story revolves around Sophie desperate to know who her biological dad is out of three of her mom’s previous relationships. After inviting Sam, Harry, and Bill to her wedding, Sophie realizes her identity is not dependent on her biological father and instead, she gains three loving step-dads. Donna does marry Sam, making him Sophie’s technical stepdad, but that has not stopped people trying to guess who Sophie’s biological dad is.

https://screenrant.com/mamma-mia-sophie-dad-sam-bill-theory/