The former TV dad and Pennsylvania restaurant host told In Touch Wednesday that his kids "live in fear of Kate."
"Every time I see them, they tell me they want to live with me," he said.
Jon said his daughters' awkward Today show appearance -- in which Cara and Mady could barely eke out a sentence despite "use your words" prompts from their mother -- inspired him to file "an emergency petition for contempt."
He said Kate didn't give him the option to watch the sextuples when she left the state with Cara and Mady. Jon said the "next step" would be a custody battle.
"I have to at least try," he added. "I just wish Kate would wake up, realize how she’s behaving and change her ways."
Kate brushed off critics of her appearance on Today in a series of tweets.
"Thanks to @TODAYshow for having Cara, Mady and me on the show today! 1st live interview can render even the gabbiest girls speechless :)" she wrote last week.