Jon Gosselin Claims Ex-Wife Kate Gosselin's Former Bodyguard 'Ruined' Their Marriage: 'Told You All'

Kate from Jon & Kate Plus 8 -- later just Kate Plus 8 -- has not publicly revealed her boyfriend's identity, however Jon seemingly believes it is the family's former bodyguard Steve Neild, who she denied having an affair with in 2009.

"I told you all," Jon wrote on his Instagram Stories on September 24, sharing a screenshot of a Page Six article alleging that Steve is Kate's mystery boyfriend.

He added: "No one believed me -- guess I was right!"

The 48-year-old didn't stop there. He then shared a photo of Kate and Steve on his Instagram grid, writing: "Guess who really ruined the marriage."

"Read for yourself."

He even shared a screenshot of the article in the following slide and directed his followers to the link in his bio which housed the article.

However, Jon isn't the only one accusing Kate of past infidelity.

Collin Gosselin -- one of Jon and Kate's sextuplets who Kate has become estranged from in recent years -- also alleged that Steve is the boyfriend in question and accused his mom of lying.

"What really upsets me is that my mom had an affair with our bodyguard back in 2009, and for years would share hotel rooms with him while we went on family vacations, while I was in the connected room," he wrote in a series of Instagram Stories Sept. 24.

"Now everyone thinks her being with him is some cute novel romance."

The 21-year-old added: "By the way my dad received death threats and got shunned by the public for years for 'having an affair' and 'leaving his kids.'"

In the series of IG Stories, Collin explained: "Everyone says my dad and I are hung up on my mom. We are not. We have suffered the damage of a narcissist and cried together. So no we won't just go and make TikTok's and act reformed when we still feel pain from our past."

Kate first announced that she'd been dating someone for the past year or so in a TikTok she posted Monday. When answering a fan asking if she's dating, Kate replied, "The answer to that question is actually, finally, yes! I am dating somebody for the past year to like, a little over a year, maybe like 15 months. I am super super happy. It’s somebody that I’ve known for a really long time and I am very very happy."

Jon & Kate Plus 8 was one of the biggest reality series in America when it launched in 2007. The nation had already been enraptured by Kate's sextuplet pregnancy and then the healthy births of her children Aaden, Alexis, Collin, Hannah, Joel, and Leah with Jon, joining the couple's older twins, Madelyn and Cara.

The series would run for a decade on Discovery Health Channel (for 2 seasons) and then TLC, during which the kids started to grow up and the Gosselin marriage completely fell apart. In 2009, Jon and Kate divorced and things grew more and more messy between the couple and their children.

Collin had previously accused Kate of abusing him when he was younger, telling The U.S. Sun last October that he'd be open to reconnecting with her if she would "come forward with the truth" about her alleged treatment of himself and his family, including his father.

Kate declined to comment to those allegations, but her attorney Richard Puleo provided a lengthy statement responding to some of Collin's claims, and defending Kate's intentions.

"There's always two sides to every story and when things take place in the past, it's hard to determine because people have different recollections and perspectives," he prefaced his remarks.

"However I can personally attest to this situation as I knew Kate and all eight of her children since they were small and I don't believe Kate ever did anything intentionally to harm Collin," he added. "I think she did whatever she did to protect her family from some of his troubled behavior as a child."

You can read all about Collin's allegations of abuse in the story here.