United Kingdom, May 8 -- Sean Penn feared he'd set his children up for "humiliation" when he cast them in 'Flag Day'.

The 64-year-old actor-and-director - who has Dylan, 34, and Hopper, 31, from his marriage to Robin Wright - got caught up in excitement when he brought the pair in to feature in his 2021 thriller and it was only later he began to experience a wave of parental anxiety about the move, so he appreciated a huge sense of "relief" when they turned in "great" performances.

He told Us Weekly magazine: "I don't know if this is true of everyone, [but] the greatest joy [in life] is often relief. It's when you take a chance with something, you invest in it.

"And sometimes with so much excitement, you forget the risk that you put yo...