Gwyneth Paltrow once had a boyfriend who used to cheat on her "all the time" and she admits not being happy when she was in her 20s.

Gwyneth Paltrow once had a boyfriend who used to cheat on her "all the time".

The 39-year-old beauty - who has kids, Apple, seven, and five-year-old Moses with husband Chris Martin - was "not happy" when she was in her 20s, but she put up with her man's stories.

The singer-and-actress - who dated Brad Pitt and Ben Affleck in the 90s - told Harper's Bazaar: "I had a boyfriend who used to cheat on me all the time.

"I was quite naive. I knew on a cellular level, but I bought his story."

Gwyneth - who counts Beyonce Knowles, Madonna and Cameron Diaz among some of her A-list friends - pointed out her and Chris have been faithful to each other, but she made an unnamed reference about one of her most famous celebrity pals.

The blonde beauty said: "I have friends who I love and admire who have had an affair. When I was younger, I would have said he's a terrible person or she's a terrible person. But who made these laws?

"She is an actress and in a new relationship with someone else with a big career.

"And I said, 'This may not be feminist, but you have to compromise. It's been all about you and you're a big deal. And if you want what you're saying you want - a family - you have to be a wife, and that is part of the equation. Gloria Steinem may string me up by my toes, but all I can do is my best, and I can do only what works for me and my family.'