The Social Network actor, 33, and Strout are now the proud new parents of a baby boy. They recently were spotted taking a stroll with their son in NYC on Monday, April 3.
Eisenberg and Strout dated for 10 years between 2002 to 2012. They briefly split but reunited in 2015.
The Justice League star opened up about their relationship — and the best love advice he’s ever received — during an interview with Seventeen magazine in August 2011.
“Oh god, I don’t know, just be nice! I’ve had one girlfriend my whole life. I’ve never been on a date with anybody else. I don’t have good advice!” he said at the time. “I find people who want to help other people to be the most interesting. I come from a family of teachers, and my friends are teachers, often times in very difficult school situations. My job is so selfish and focused on my own vanity that I like to surround myself with people who are actually helping people throughout their day.”