The 56-year-old split with the Housewives Of Beverly Hills star last year after meeting current wife Kayte Walsh, and is trying to get sole custody of their children, Mason, nine, and Jude, six.
Camille has filed her own application for sole custody to counteract Kelsey's, meaning that it will be up to the courts to decide who the children live with.
And speaking at the Tony Awards with Walsh, 30, by his side, he warned Life & Style magazine, 'It's going to be a long, drawn-out thing. We'll be tortured and it will be unpleasant I'm sure, but not on my side.'
But does he think that he and Camille will ever be on friendly terms again?
'I really can't tell,' he said. 'It's very hard at this point. I'm not going to say much about that, but I'm going to do my best to make sure my kids are always okay.'