Sarah Jessica Parker says time apart from Matthew Broderick benefited their marriage

Sarah Jessica Parker is getting candid about her relationship with husband Matthew Broderick.

The 52-year-old actress appears on the latest episode of Girlboss Radio hosted by Sophia Amoruso, where she talks about her longtime marriage with Broderick. The two have been married for 20 years and share three kids together -- son James, and twin daughters Marion Loretta and Tabitha.

Parker says her and the 55-year-old Broderick's busy careers are actually beneficial to their marriage.

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"I know this sounds nuts, but we have lives that allow us to be away and come back together," she explains. "His work life takes him here, and mine takes me there. In some ways, I think that that's been enormously beneficial because we have so much to share in a way... anytime that any relationship is hard, it's the point in which you're deciding, is this worth the investment getting through whatever that thing is?"

"Relationships are hard. I always felt that I wanted to invest more," she continues. "I love him, and I think he's brilliant. I'm sure I annoy him. He annoys me sometimes. I'm enormously proud of the person he is. I think the longer you can last, the more invested you just are."

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Later, Parker gets candid about how motherhood has changed her.

"You're in a constant state of worrying about your children," she admits. "It's very painful and it's exhilarating. It's a really interesting way of living in the world. I read books differently, or I look at parents and children on the subway differently. I hear music differently, or when I see something, I think, 'I wish Tabitha and Loretta were with me now and they could see this.' That's the good part."

Of course, there have been a few hardships.

"It's not for everybody, there's a lot that's really hard," she says bluntly. "It's exhausting and you're basically just cleaning up after people all day. You're one big, good, old-fashioned secretary. All I do is organize people's lives and get them here and there and all that. It's what I wanted and with that, though, comes witnessing somebody hopefully develop into a really interesting, decent person who contributes something."

ET spoke to Parker earlier this month at the Golden Globes, when she talked about nixing a third "Sex and the City" film.

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