Brad Pitt says marriage to Angelina Jolie is 'something we've got to look at'

Brad Pitt seems to realize that he and Angelina Jolie have an unconventional relationship. The two have six children together - three adopted children, Maddox, Pax and Zahara, and three biological children, Shiloh, Knox and Vivienne, but have yet to tie the knot.

Pitt tells USA Today his children, whose ages range from 2 to 9, "ask about marriage." He adds, "It's meaning more and more to them. So it's something we've got to look at."

The actor stars in the new film "The Tree of Life." The film is currently in limited release, and tells of three young brothers in the 1950s in the Midwest. Pitt plays their father and his character's oldest son, who is 11, witnesses the loss of innocence. Sean Penn portrays the boy when he is an adult, who tries to reconcile with his father.

"Our kids have to live behind a gate. Outside, there are people with cameras," Pitt tells the newspaper about his children's lives. "But I'll take the trade-off. I never knew I was capable of experiencing so much love."

"Angie and I do everything we can to carve out some semblance of normalcy for them, to re-create the kinds of moments that were special for us. It's not unusual for the kids to be covered in paint," he adds. "We have mud fights. It's chaos from morning until the lights go out, and sometimes after that."

The actor adds that not only does he spend quality time with his kids, he and Jolie make time together as a couple and they'll let the children know when they need their private time.

"There are no secrets at our house," the actor said. "We tell the kids, 'Mom and Dad are going off to kiss.' They go, 'Eww, gross!' But we demand it."

Pitt recently told OnTheRedCarpet.com host Chris Balish at "The Tree of Life" premiere that if his kids see the film, "I'm hoping when my kids grow up, they'll go, 'Dad's a pretty good actor because that's not him.'"

Jolie accompanied Pitt to the Los Angeles premiere of the movie on Tuesday, May 24, and wore a red (or poppy), one-shoulder, silk, chiffon Jenny Packham gown with a velvet waistband .

Pitt also addressed the recent deadly tornado that struck the town of Joplin, Missouri, where his mother and late grandparents once lived, saying: "My thoughts are certainly with them."

Watch the trailer for "The Tree of Life" below.