The Irwins are hardly the first family that comes to mind when you think of messy dramas – but members of the famous conservationist clan are today trading surprisingly candid barbs publicly.
The feud suddenly exploded on the weekend over a sweet Father's Day post Bindi Irwin shared, paying tribute to her own father Steve, her husband, Chandler Powell, and her father-in-law.
One fan asked Irwin why she left her grandfather Bob out of the tribute – and she didn't hold back, accusing Bob of years of "psychological abuse" in an uncharacteristically candid response.
"Unfortunately my grandfather Bob has shown no interest in spending time with me or my family," she wrote.
"He has never said a single kind word to me personally. It breaks my heart but it is not healthy to engage in an abusive relationship … I have struggled with this relationship my entire life and it brings me enormous pain."
It didn't take long before Bindi's surprising allegations were met with a response.
Family hit back: 'The lies need to stop'
Another member of the family angrily disputed Bindi's claims in a Facebook post of her own, defending Bob or "Poppy" as she affectionately calls him.
Bethanny Wheeler explained that she is the " granddaughter of Bob Irwin via marriage of my father and my Stepmother Mandy as a very young child," and called Bob "the most genuinely beautiful human on this planet and has NEVER spoken out or put down anybody! He is a man who sits silently and battles his demons alone, in what is great sadness. He doesn't retaliate, only prays for his grandchildren's safety and good lives".
Wheeler wrote that her "sisters and brothers will happily back me up when I say that Bob Irwin is a passive and beautiful human and these lies need to stop".
Bob Irwin's biographer also came to his defence, saying he had been "devastated" by Bindi's claims of abuse.
Amanda French, who co-wrote Bob's 2016 autobiography The Last Crocodile Hunter, took to Facebook to defend his character and slam Bindi.
"To write that there is psychological abuse from the kindest, most beautiful soul I have ever met, is heartbreaking," she wrote, saying Bob has been "devastated to his core".
"Unbeknownst to you, and what you know, he is suffering deeply for the loss of his family … He has done all he knows how to do and that is bury his head in the sand because that's how he copes," she continued.
"He's not someone who is out there about reaching out and communicating, he's like your Dad was. An introvert and not someone who can navigate people well.
"He loves your Dad, and you guys more than you know. This should be a private matter not written about on Facebook."
Entertainment Reporter Peter Ford told Sunrise on Monday that he spoke to Bob's wife Judy over the weekend who was unaware of Irwin's comments.
"They were pretty shellshocked by it and when I rang and read to his wife Judy the details, they're not on social media, so they were not aware of what was going on at all, I think they were pretty shocked and devastated. That's just the feeling I got. They didn't say that to me and they did not come back and offer any kind of reply or response."
Bob and Steve's close bond
It's a sad new development for the Irwins given just how close Bob and son Steve were before Steve's death in a freak stingray attack in 2006 aged 44.
Steve had boundless enthusiasm about his fellow conservationist father, who he dubbed "the legend of the universe".
Steve told the ABC's Enough Rope in 2003: "He was everything I wanted to be. And all I've done in my life is follow in his footsteps, mimic him and try to be him. And nowadays I just try to make him proud."
The father and son had just wrapped up a month-long crocodile research project in Cape York when Steve was killed in his September 2006 freak accident.
"You never expect that's the last time you're ever going to see your son, but I certainly had a feeling he sensed something was about to happen," Bob said after the accident, in which Steve died after being pierced in the chest by a stingray barb while filming on the Great Barrier Reef.
Announcing his book's release in 2016, Bob said that "when the world lost Steve, the animals lost the best friend they ever had, and so did I."
"What he stood for and what he was able to achieve means just as much now as when he was here in the physical world."