In an all-new exclusive interview, ET's Mary Hart sits down with Jon Gosselin -- and the controversial TV dad gets candid on how his ongoing feud with estranged wife Kate is affecting their kids. Plus, he reveals how he plans to deal with seeing Kate face-to-face at the upcoming birthday of their twin daughters, Mady and Cara.

"As my old self, as an avoider and passive, I want to go home for Cara and Mady -- but I don't want to face [Kate]," Jon tells ET about going home for the twins' birthday on Thursday.

"We'll just put on a happy face… and do what's best for Mady and Cara," Jon adds.

As the battle between Jon and Kate ensues, the dad of eight opens up to Mary about how their children are coping.

"It's already had an impact on the kids. This thing has gotten so crazy and we've let too many people in, and everything's going haywire…," Jon says. "They didn't ask for this. It's not their fault. But it is our fault by throwing our kids out there, shoving a camera in their face and asking an eight- or nine-year-old to explain it."

Jon also claims Kate speaks negatively about him to the kids, saying daughter Mady "can't keep a secret" and tells him what she says right away. But Jon claims he isn't worried about what Kate tells the kids because, "they know that they're safe with me."

Watch tonight's ET for more of Mary's revealing new interview with Jon -- and click here for a look at ET's photo gallery of the Gosselin kids!