Actor Will Smith discussed his marriage to Jada Pinkett Smith, revealing that the nearly 20 years they've been together have been filled with ups and downs.

"You can't expect it to be easy," the actor, 47, told Entertainment Tonight. "It's like our marriage was the most difficult, grueling, excruciating thing that we have ever taken on in our lives. And you know we're just not quitters."

Smith—who married Pinkett Smith in 1997—also shared the secret to their marriage. "If there is a secret I would say it is that we never went into working on our relationship," the movie star revealed. "We only ever worked on ourselves individually, and then presented ourselves to one another better than we were previously."