Angelia Jolie says her son Maddox watched R rated movies behind her back for years.

When you’re a parent, you have to accept that there will be times when your kids get up to mischief behind your back.

And it turns out that Hollywood power couple Angelina Jolie and Brad Pitt are no different.

Jolie recently revealed in an interview with People that her 14-year-old son Maddox had been secretly watching R-rated movies behind her back – for years. Oops…

The 40-year-old, who is also mum to Pax, 12, Zahara, 10, Shiloh, 9, and twins Knox and Vivienne, 7, was sharing parenting anecdotes with her Kung-Fu Panda co-star Jack Black when she revealed Maddox was a bit of a rebel.

“You think the kids know nothing, and then you find out they’re like, ‘Oh yeah, seen it.’ That happened like four years ago," she said.

During the interview, Black said he wouldn't like his children to watch any of his own R-rated flicks, such as The Pick of Destiny, which features the actor smoking a bong with Satan.

WATCH Angelina Jolie discuss acting, marriage and motherhood. Post continues after video...

But Jolie replied:“Whereas my eldest probably already has. My oldest especially loves Jack’s music. He’s introduced him to a few words, few thoughts.”

Ah, kids - always in a hurry to grow up too fast...

Do you let your kids watch R-rated films?

TAP on the image below and scroll through the gallery to see the whole Jolie-Pitt clan...