Sheryl Crow admits she's a strict parent.

The singer - who has two adopted sons, Wyatt, three, and 11-month-old Levi - believes it's important for children to have boundaries and doesn't think it's a good idea when parents try to act like friends.

She said: "I'm strict. I think one thing that is missing now with kids is the hierarchy of adults not being friends, even though ultimately that's what you want with your kids. They have to understand that somebody's in charge and sometimes The Answer is no. It's about being consistent."

Sheryl, 49, also revealed how she is careful about introducing her sons to her boyfriend as she knows how difficult it can for children if they were to split up.

Sheryl - who has been dating an unnamed producer for several months - told Prevention magazine: "I've been in the situation where I've been involved with people and their kids, and if the relationship doesn't work out, it's heartbreak. So I'm keeping the relationship friend-based when we're around the kids."

While she's happy in her relationship at the moment, Sheryl doesn't plan for the long-term future.

She said: "I'm pretty set in my ways, and whoever I'm going to end up with, God willing, will have gone through their things too. So I'm not looking at having a fifty-five-year relationship. I'll be happy if I have a ten-year relationship."