Seyfried dated her Mamma Mia! co-star Dominic Cooper on and off from 2008 to 2010, and actor Justin Long from 2013 to 2015.[55] Seyfried began dating actor and The Last Word co-star Thomas Sadoski early in 2016.[56] The couple confirmed their engagement on September 12, 2016,[57] and in March 2017, got married in a secret, private ceremony.[58] On March 24, 2017, it was announced that Seyfried had given birth to the couple's first child, a daughter.[59][60][61]