Whoa... Conan O'Brien reportedly STOPPED guests at his holiday party from calling 911. The fight Rob and Nick Reiner had was that intense. Yikes. It's been the tragedy that stunned the nation. On Sunday, director Rob and his wife Michele were found dead in their Brentwood home. Their son Nick was arrested and charged with the crime. Rob and Michele spent their final moments at Conan's Christmas party on Saturday night, where the 32-year-old Being Charlie screenwriter was said to have been acting off. He showed up in a hoodie (despite everyone else in nice attire). He largely kept to himself, but when he did engage with folks, it was off-putting. He was called "crazy" for constantly asking people if they were famous and even storming off after a "tense" interaction with Bill Hader. Yeesh. Related: How Rob & Michele's Close Friends'Fiercely' Protecting Kids After Murders Apparently the famous couple left shortly after Rob and Nick got into a "very loud argument," which was overheard by many there. We still don't know what they said, but by all accounts it sounds like it was SUPER serious! An insider spilled the tea to DailyMail.com on Friday. According to them, the argument was so heated, several guests at the ritzy party actually wanted to get the cops involved! "They got in an argument, the father and son [at the party]. It got so bad and loud [that] someone wanted to call the police to report it." Wow. That's how you know things were REALLY alarming! However, the police ultimately weren't involved - because the former late-night host allegedly shut it down! "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." He obviously could never have known what was going to happen next. If this report is true, we know in that moment he was making a decision he thought was best for his friend. Nothing that happened afterward is his fault. It was a party full of celebs and industry folks, the last thing he must've wanted was cops pulling up and the press arriving. If only we could turn back time... A second insider doubled down on this, telling the outlet that many guests were worried that Nick needed to be placed on a psychiatric hold. Oof. The insider explained: "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." Man. That says a lot about how he must have been acting. But, again, cops weren't called: "Conan O'Brien stepped in and said, 'no, I don't want the police at my house.' It makes sense; who wants the cops showing up creating a scene? But the argument between Rob and Nick was pretty intense." According to another insider, an unnamed celeb revealed that after Nick stormed off, Rob told some of his friends 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." So, it's really no wonder the guests were on edge. It sounds like it must have been a really dark and dramatic situation that unfolded. How horrifying for all those guests to wake up hours later to discover what happened. Ugh. Just heartbreaking. A source close to the Los Angeles Police Department confirmed there were no 911 calls placed from the home that night. Reflecting on the haunting "what if," the first source remarked: "Only the murderer is responsible. ... But it must be gut-wrenching for Conan to learn that this is how things turned out. I'm sure that night is replaying for him over and over. It's just so awful and sad." Nick is currently in custody and said to be on suicide watch. Per TMZ, he had been diagnosed with schizophrenia, for which his parents had sent him to a nice rehab facility to help treat him recently. Just a few short weeks before the killings, his docs started switching up his medicine to help stabilize him as his behavior was growing "erratic and dangerous." Sadly, it only made it all worse (and his addiction issues also exacerbated the matter). Our hearts go out to all those mourning this tremendous loss, especially the Reiner family and those who saw the couple in their final moments. For resources on mental health, visit https://www.nimh.nih.gov/health/find-help. [Image via MEGA/WENN & Michele Reiner/Instagram] The post Conan O'Brien Stopped Party Guests From Calling 911 After 'Intense' Fight Between Nick & Rob Reiner: REPORT appeared first on Perez Hilton.