Rob Reiner, his wife Michele, and their son Nick attended Conan O’Brien‘s Christmas party Saturday night. At the party, Rob and Nick got into a “very loud argument,” loud enough for many others to hear … Reiner family sources tell TMZ. We’re told Rob and Michele then left the party. We do not know if Nick left as well.

TMZ is the first to report the argument between Rob and Nick on the heels of the murders.

Our family sources add … Michele had been anguishing to friends over the last few months that she and Rob were at their wits’ end over Nick’s mental illness and alleged substance abuse issues, and did not know what to do with their son Nick … saying, “We’ve tried everything.”

Carl Carlton — best known for his smash hit “She’s a Bad Mama Jama” — has died at 72.

The sad news was confirmed by his son Carlton Hudgens II, who announced his dad’s passing on Facebook … sharing a throwback photo of the late singer and writing, “Long hard fight in life and you will be missed.”

The cause of death hasn’t been revealed, but the passing comes six years after the singer suffered a stroke.

Carlton launched his music career back in the ’60s, later hitting the Billboard Hot 100 Top 10 in 1974 with his cover of “Everlasting Love.”

Rob and Michele Reiner‘s son Nick has been arrested and is being held on $4 million bail, TMZ has learned.

The 32-year-old is in the custody of the Los Angeles County Sheriff’s Dept. as of Monday morning, according to online records. He was booked at the LAPD jail.

As we reported … the couple was found by one of their daughters Sunday with their throats slit inside their Los Angeles home.

Friends and collaborators, Billy Crystal and Larry David, were seen leaving the couple’s home Sunday evening looking very distraught.

An outpouring of tributes have come in following the tragedy, including those from Barack Obama, Stephen King, and Ben Stiller, among others.