Rob Lowe's Son John Hilariously Trolls Him from Backstage During Ellen DeGeneres Interview

Aurelie Corinthios

There’s nothing like getting roasted by your offspring on television.

In a sneak peek at his appearance on The Ellen DeGeneres Show on Monday, Rob Lowe sits down to catch up with host Ellen DeGeneres — all while his son John Owen, 24, is backstage, poised to comment on the interview.

Lowe, 55, starts by proudly listing his son’s accomplishments. (The recent graduate is currently writing for prolific TV creator Ryan Murphy.)

“He graduated with straight As at Stanford,” Lowe says. “Got in because he was the earliest intern in Eli Broad’s stem cell laboratory. Got out and decided he wanted to be in Hollywood and I wanted to kill myself.”

“He’s a very smart kid and he’s doing great,” he adds, before sharing an update on his elder son Matthew Edward, 26.

“Matthew, my oldest, just passed the California bar,” he says. “It’s one of the hardest tests in the world. He’s carrying on a good legacy, because my dad’s an attorney and I only play them on television.”

RELATED: Rob Lowe Throws Shade at Alleged College Admissions Scam — ‘Very Proud of My Hardworking Sons’

“His boys, basically, they always comment on [his] Instagram posts,” DeGeneres explains to the audience. “So Johnny is backstage right now and so he’s going to watch this entire interview and comment as we go.”

“They troll me, I think as the kids call it,” Lowe says. “It’s going to be brutal.”

First up, DeGeneres, 61, pulls out a copy of PEOPLE’s recent Sexiest Man Alive issue, which features Lowe in the “Sexy at Every Age” spread.

Teases John from backstage, “You should ask him how many times he’s been on the cover.”

“You haven’t been on the cover, not for lack of examples why you should be — let’s show some examples,” DeGeneres says, pulling up a series of shirtless photos of Lowe.

“I’ve never been the Sexiest Man Alive,” Lowe says. “Never! There’s always been somebody sexier, and I’m very angry about it. I think the only reason I have not been Sexiest Man Alive, and I’ve spent a lot of time thinking about it —”

“Please stop, guys,” John pings, interrupting them. “Honestly surprised he’s not shirtless right now!”

Continuing, Lowe jokes, “I blame Russian collusion, honestly. This is an election I should have won.”

Michael Rozman/Warner Bros.

DeGeneres then starts asking Lowe about a photo he took with a giant, ancient tortoise in the Galapagos islands.

“Just a bunch of dinosaurs hanging out. Rob fits right in,” John jokes.

Last but not least, the conversation turns to Christmas.

“I have an obsession. You know me — I’m not really involved in the house, I live in the house, I love the house, but that’s [my wife] Sheryl‘s domain,” Lowe says. “But when it comes to the Christmas tree, I am all over it. I’m obsessed with it drying out too soon.”

Chimes in John, “It’s the only thing he’s ever done around the house.”

“He’s right about this,” Lowe admits. “I have a phobia about the pine needles, they get all brittle and fall and then they’re just going to be flammable.”

To keep the tree alive, the actor says he mixes 7UP in the water: “It’s half 7UP, half water. I am obsessed with this. This is all I care about during the holidays.”

As for when the tree gets taken down in the Lowe household?

“Sheryl don’t disagree on much, but we disagree on this — I like to have a little afterglow,” Lowe says. “She literally has that tree out of the house by lunch on Christmas Day.”

Ellen airs weekdays (check local listings).