Before they were reality TV royalty with 'Keeping Up With the Kardashians,' the family had a long-rooted friendship with the former football player.

Exactly 25 years and one day after O.J. Simpson became a suspect for the murder of his ex-wife Nicole Brown Simpson and her friend Ron Goldman, he made a bold move: The former football star joined Twitter.

Launching the Twitter handle TheRealOJ32, Simpson made it clear in the video he posted June 15 that he’d be using the social media forum to “set the record straight.” His first order of business: Declaring that he isn’t Khloe Kardashian’s father.

Bob Kardashian, he was like a brother to me. He was a great guy,” Simpson said in his third Twitter video, ironically posted on Father’s Day. “He met and married Kris and they really had a terrific time together, when they were together. Unfortunately, that ended. But I never — and I want to stress, never in any way, shape, or form — have I ever had any interest in Kris romantically or sexually — and I never got any indication that she had any interest in me.”

After calling all those stories “bogus, bad, and tasteless,” he continued, “Khloe, like all the girls, I am very proud of, just like I know Bob would be if he was here. But the simple fact of the matter is that she is not mine.”

Khloe had already confirmed that fact by taking a 23andMe DNA test in an October 2018 episode of Keeping Up With the Kardashians, revealing she’s “58 percent European, 41.6 percent Middle Eastern” — meaning Robert Kardashian really is her father.

Even though there reportedly aren’t any genetic ties, the relationship between Simpson and the Kardashian family still goes way back.

Robert Kardashian and Simpson met while they were college

Robert Kardashian first crossed paths with Simpson around 1967 when he was a “waterboy” for the University of Southern California football team while Simpson was a running back, according to Slate. They later met again while playing tennis at a mutual friend’s house.

The two quickly developed a friendship and also became business partners, including investing in a company called Juice Inc., which opened frozen yogurt shops, first named Joy and later Forty Carats, as the L.A. Times reported. They also invested in Concert Cinema, which would show music videos before movies in theaters.

Simpson and Kardashian trusted each other implicitly. Before buying the Rockingham Estate in Brentwood, Simpson reportedly asked Kardashian for his opinion.

The Kardashian siblings called Simpson 'Uncle O.J.'

Soon, the friends brought wives into the mix. Kardashian married San Diego-born Kristen Mary Houghton (later Kris Jenner) in 1978 and Simpson, who was married to first wife Marguerite at the time, eventually got divorced and remarried to Nicole Brown.

“Nicole brought O.J. a lot of happiness — you could see it. She lit up his life,” Kris said, according to Slate. “They were golden together.”

As they started their families, the Simpsons and Kardashians remained closed. Simpson visited the Kardashians in the hospital when first daughter Kourtney was born. The families often vacationed together and the Kardashian kids referred to the Simpsons as “Auntie Nicole” and “Uncle O.J.”

Kris even believes she was with Brown in New York City when she bought her husband the gloves that would later become crucial evidence in the trial.

But the good times didn’t last. Both couples went through divorces together: the Kardashians in 1991 and the Simpsons in 1992.

Simpson's trial put a huge strain on the Kardashian family

The Kardashian name first made national headlines when Robert became Simpson’s lawyer in the June 12, 1994 murder of Brown and Goldman. But the irony is that Kardashian hadn’t been in a courtroom for two decades and hadn’t even been a lawyer for 15 years. But he quickly reactivated his law license and came to the aid of his friend, firmly believing Simpson’s innocence.

However, Kris, who later married Caitlyn Jenner (then Bruce Jenner), didn’t feel the same way. Daughter Kim Kardashian West told Dr. Phil this created a huge strain in their family: “We really felt in the middle of this trial. We didn’t know which parent to side with.”

Kris felt like she 'failed as a friend' to Brown

In fact, the trial wasn’t the only effect Simpson had on the young Kardashians’ lives. Simpson also threatened his own life in 13-year-old Kim’s bedroom. While the teen wasn’t home at the time, her father stopped Simpson from committing suicide by pleading, “I could never walk in this room. My daughter couldn’t sleep in this bed. She’d know what happened,” as he recalled to Barbara Walters.

Kris, who has since said she felt she “failed as friend” to Brown, supported Brown’s family and was in the courtroom, pregnant with Kendall Jenner, during the verdict. But the most moving way she honored her late friend: By giving Kendall the middle name of Nicole.

As the model-social media celebrity confirmed in a Snapchat video: “My middle name is after Nicole Brown Simpson because that was my mom’s best friend. And I’m honored to have this name.”