Show business has brought Britney Spears fame and fortune, but it's the downside she wants to avoid when it comes to her kids. She is going to work at all costs to make sure her sons live the private life.

She told Cosmopolitan, "If my sons told me they wanted to be in the entertainment business, I'd lock them in their rooms until they turned 30."

She also said she's fearful of the day she has to tell Sean Preston, 4, and Jayden James, 3, about the "birds and the bees."

"I'm dreading the moment when my sons ask me how babies are made," Spears said.

"Things are pretty quiet right now. I've been spending a lot of time at home with my boys," she told the magazine. "They just started karate class, which is super cute!"

Britney Spears' full interview is in the August issue of Cosmopolitan.

More: Celeb Photo Features | Fashion Photo Features

Click for more great Britney Spears pictures: