United Kingdom, April 28 -- Brenda Song can understand why some couples "break up" when they have children.

The 37-year-old actress has been in a relationship with 'Home Alone' star Macaulay Culkin, 44, since 2017, and has Dakota, four, as well as two-year-old Carson with him, but insisted that "high-stress situations" in the early days of parenthood can sometimes lead to a split.

She told E! News: "No matter how well you know your partner, when you have kids, it's another phase of your relationship, because you are dealing with situations that you've never dealt with.

"You're raising little humans together. It comes down to this really ground level of who you guys are and if you connect.

"[I understand] why people break up when they ...