The actor and the "Suite Life" star have been together for four years and are going to marry shortly, according to People. They welcomed their 9-month-old boy Dakota last April.
Representatives for the couple have been contacted by CNN for comment.
"We're ecstatic," Culkin and Song stated in a statement after their kid was born.
They met on the set of Culkin's pal Seth Green's film "Changeland" in 2017. They've kept their romance under wraps, with Song disclosing on social media that they're both homebodies. "Very few things can get us out of the house and away from our kid," she captioned a photo of the couple on a date night in November at a Los Angeles Rams game.