Conan O’Brien stopped guests from calling 911 on Nick Reiner during explosive fight with dad Rob at holiday party: report

Conan O’Brien reportedly stopped guests from calling 911 on Nick Reiner during his explosive fight with his dad, Rob Reiner, at the comedian’s holiday party on Saturday — hours before Rob and his wife, Michele Singer Reiner were found dead.

“They got in an argument, the father and son. It got so bad and loud someone wanted to call the police to report it,” an insider familiar with the event told Daily Mail on Friday.

“But Conan stepped in and said, ‘It’s my house, my party, I’m not calling the police.’ He talked them out of calling the police.”

A second source echoed the first insider’s comments, adding that guests worried that Nick needed to be placed on a psychiatric hold due to his behavior.

“When the s–t was hitting the fan, somebody said we need to call the police. The conversation was about getting this kid put into a mental-health hold,” the source told the outlet.

“It makes sense; who wants the cops showing up creating a scene?” the insider noted of O’Brien’s alleged decision to keep the police from intervening.

“But the argument between Rob and Nick was pretty intense.”

A rep for O’Brien did not immediately respond to Page Six’s request for comment.

The news comes shortly after it was revealed that the late film director shockingly told close friends he was “petrified” that his son could “hurt” him before he left O’Brien’s party that night.

A source who allegedly attended Rob and Michele’s memorial service on Monday told Daily Mail that guests were left in tears after an unspecified A-lister recalled the “All in the Family” star’s last words at the party.

“I’m petrified of [Nick]. I can’t believe I’m going to say this, but I’m afraid of my son. I think my own son can hurt me,” the celeb alleged Rob said.

As previously reported, a source confirmed to The Post that Nick and his parents were involved in a massive verbal spat at O’Brien’s party on Dec. 13, just one night before Rob and Michele were found stabbed to death in their Los Angeles home.

According to multiple outlets, Nick was not only acting out with his parents, but he also acted erratically with some of the other party goers in attendance that night including comedian Bill Hader.

“Nick was freaking everyone out, acting crazy, kept asking people if they were famous,” an insider previously told People. Another source alleged to Us Weekly that Nick behaved “creepily” at the fancy party.

Sources told The Post that the couple’s slain bodies were eventually discovered on Sunday by their daughter Romy Reiner.

The insiders alleged that the pair were found with their throats were slit and with stab wounds to their throats along with other wounds found throughout their bodies. Rob was 78. Michele was 70.

On Wednesday, the Los Angeles County Medical Examiner’s Office revealed their official causes of death were listed as “multiple sharp force injuries.” The manner of death for the parents was listed as a homicide.

Nick was arrested later that evening and is now facing two counts of first-degree murder for his parents’ deaths.

Nick made his first court appearance since his parents’ deaths on Wednesday where he received a Jan. 7, 2026, date for an arraignment in his case.