Will Smith Can't Parent on Set

For a second year in a row, Will Smith is co-starring with one of his offspring in a major motion picture, hitting big screens Dec. 14 in I am Legend with daughter Willow. The two may be father and daughter in real life, but when cameras started rolling, the actor’s parental rights were revoked.

"I'm not allowed to talk to the kids while they're working,” he tells Entertainment Tonight. “Jada Pinkett Smith says, 'Once the movie starts you are their co-star and I am their mother. Any problems you have with those kids you can talk to their mother.'"

The two-time Oscar nominee may have to get used to that rule as he envisions many more future projects for Willow, 7, and 9-year-old Jaden, who co-starred with his dad in last year’s The Pursuit of Happyness. "Entertainment is our family business. It's what we do, it’s how we eat, so at some level everyone is involved in the process."

As for their marriage, Will and Jada are coming up on the 10-year mark on Dec. 31, a lifetime in Hollywood. And don’t think it didn’t come without work. The 39-year-old reveals the couple take time out to study their relationship and iron out the kinks in the midst of parenting and bustling film careers.

“I've probably got 40 books under my belt on making relationships work,” he says. “If you're going to spend 60 hours per week working at your job and it takes you 60 hours per week to be successful at that job, you think with two hours a week and sex on Saturday night you're going to make the most important relationship of your life work?"

And you can bet the clan, which also includes Will’s son Trey, 15, from his first marriage, will carve out quality time together for the holidays. A stickler for tradition, Jada is serious when it comes to Christmas, Will says, annually researching the places with the most snowfall for family to trek to.

“We'll be in Denton, Mont., because they have projected 14 inches of snow on Christmas Eve. We have a tradition, a Christmas Eve sleigh ride."

And what will he give Jada for Christmas?

Will won't reveal it, but adds, "Jada is very simple so big gifts fail horribly."

For more on Will, tune into ET tonight.