After revealing that he thinks the former vice presidential candidate had a "cougar crush" on his much younger self, Johnston is now telling E! News that Sarah and her snowmobile-jockey husband, Todd, don't even sleep in the same bed.
In fact, Todd's been banished to the couch.
"Todd slept on a little black leather sofa, not even a comfy one! And Sarah always slept in the bed. Since I've known the family, that's how it's always been,"Johnston exclusively tells us.
Oh and he's not stopping there. Levi, who once tried to make amends with the Palins (and tells us Sarah used to refer to him as her "second son"), also says he's preparing to take baby mama Bristol to court because she is trying to prevent him from seeing their baby, Tripp, by taking the tyke out of the state.
"Oh yeah, you betcha," Levi says of going to court, mimicking Sarah's famous line before catching himself and quickly adding: "I probably shouldn't say that."
Levi says he's legally supposd to see Tripp twice a week, but that Bristol "makes that impossible," and he's only seen his boy once in the past month. He doesn't like the idea that people see him as a deadbeat dad.
"I know that's what everyone says, the media, it's ridiculous what she says," Johnston says. "I didn't give Bristol's book the time of day."
He also tackles the touchy subject of Bristol's claims she was date-raped by him after a number of wine coolers and that he "stole" her virginity.
"We dated for several years and made love," he tells us. "For her to say something like that, that's just a road you should never go down.
"She was not drunk. I was buzzed...It's unbelievable. It takes two. I don't know what else to say."
Finally, he says he is still holding out hope that one of his reality-TV pitches will catch on so he can get some income to support his son. Failing that, he is also planning to start a tour-guide company with his dad and he wants to get his pilot's license.
"This is the truth," he tells us. "I just want to see my son."