On November 29, 2016, Thomas and his then fiancee,
Amanda Seyfried, announced they were expecting their first child in spring 2017; a few days later, during a different interview with W magazine, Amanda unintentionally revealed they were expecting a boy. The "W Magazine" interview appeared in the January 2017 issue. However, the revelation turned out to be incorrect, and when their first child was born on March 21, 2017, they named her
Nina Sadoski (full name: Nina Seyfried Sadowski).