The 'How to Lose a Guy in 10 Days' star - who has Ryder, 12, and Bingham, five, from past relationships - doesn't like to speak publicly about any men in her life until she has introduced them to her kids.
She said: "The reason I don't talk about anything like that is because I have kids.
"People ask that question as if, 'Oh yeah, it's really healthy to publicly talk about who I am or am not dating when I've got a tween.' [Ryder] can read, and he can hear. I'm not going to indulge in that kind of thing until there's someone in my life who I am introducing to my kids."
The 37-year-old actress split from Matt Bellamy in 2014 and admits "forgiveness" is a big thing to deal with when any relationship ends.
Speaking to the October issue of Marie Claire magazine, she shared: "I think forgiveness is the biggest part of it ... I think everybody wants to point fingers.
"If you are a person who takes responsibility for yourself and your part in it, you have a much better chance of maintaining a nice relationship. It also means that you grow up. A lot of people don't want to grow up because it sucks."
Despite not wanting her kids to read rumours about her relationship status, Kate otherwise loves to embarrass her son.
She shared: "I'm loving the preteen [experience]. His hormonal moods are so fun for me, because it makes for so much comedy!
"I tried to hold Ryder's hand the other day in public, and he was like, 'Mom, please don't'. And then I just grabbed his hand, like, 'I'm gonna grab your hand!' And it became funny."