Hide the kids and get the lawyers on the horn, this thing is getting ugly.
"You know me, I don't come home when she's with the kids, because I respect her time with the kids," said Jon. "She tried to come home yesterday, and I wouldn’t let her in the gate. I guess she called the police, and the police came.
"They said it was a civil matter, and we would have to work it out with our attorneys," he explained. "The officer pulled me aside, and I'm like, 'This has never happened before, and I am spending time with my kids, and she's going to have to leave.' "
After the police arrived, Kate ultimately calmed down and left the grounds for a local hotel. She has yet to address the press.
So why was Kate so adamant about coming in the house while Jon was there?
"I guess she didn't agree with my babysitting, but you know, I didn’t approve hers," he said. "She didn't agree, and that is something with we will have to work out with our attorneys and custody and all that."
The babysitter in question: cocktail waitress Stephanie Santoro, with whom Jon's been alleged to have had a fling.
Jon said there was nothing scandalous going on: "I called my babysitter Steph, and she came over and watched them for filming, and she's just always available so…like, some of our babysitters live far away, but I had to get things done."
Asked if he approved Kate's babysitters? "I guess if she'll approve of mine," says Jon. "It's kinda like back and forth."
The blowup was curious, in light of comments both have made recently about staying civil for the benefit of the children.
During her Live interview, Kate was asked about how things are going with figuring out who sees the kids when. "Surprisingly, that is the most peaceful part of it. We do work pretty well together with the kids," she responded.
Kate spent the day runninng errands around town and didn't talk to reporters about the dust-up.
Thursday's shouting match was, Jon admits, the first time in a long time he has seen Kate.
For the kids' sake, let's hope the next time Jon and Kate meet, the cops don't have to be called.
Want to hear from the other woman? You're in luck. Jon's girlfriend, Hailey Glassman, gives her first-ever TV interview to E! News on Monday at 7 and 10 p.m.
And be sure to check out our pictorial account of the Reality of Jon & Kate Plus 8.