Bindi's grandad won't be at her 16th birthday party on 24th July. The man who founded Australia Zoo will be working on a crocodile conservation project in Cape York.
Nobody knows if he got an invitation or not, but because he won't be there, everyone is assuming he's still angry with Steve's wife Terri for not letting the children visit him when he had a heart attack in 2010.
Terri said they were in America when it happened and hoped that Bob would now stop smoking - ouch! I get the feeling that is something you wouldn't say to a tough old bird like Bob Irwin. But he seems to have mellowed over time.
"I think Terri's done a great job job with those children, she's had to raise them herself" he said. "They are well-adjusted children and have a good background with their dad, nobody could be more down to earth than Steve was, and they've got a great future ahead of them."
Bindi's party has been advertised as the biggest "onesie" party in the world and everyone has been asked to come to Australia Zoo dressed in an animal onesie (a one piece jump suit for relaxing).
But it hasn't been plain sailing for the Irwins this year. In March, Bindi outraged animal rights groups when she announced on Good Morning America that she would be working with SeaWorld to encourage "kids to change the world."
SeaWorld is having a bad image problem brought about by the award-winning film documentary Blackfish, which probes the treatment of killer whales at Sea World's parks. US-based PETA started a campaign against SeaWorld and blasted the Irwins.
"The Irwin family has been exploiting animals for years so it comes as no surprise that Bindi has agreed to become SeaWorld's latest shill" a PETA spokesman said. "But plastering her face on Sea World's website won't cover up the fact that orcas, dolphins and other animals are suffering in Sea World's tiny tanks after being ripped from their families."
So Bindi's birthday party will go ahead without her grandad which seems a shame. "This is not about Bob Irwin the wildlife warrior or Bindi Irwin the television star - this is about a grandad and his grandchildren" Bob said back in 2010.
Steve's affection and respect for his father was well known, he even called his son after him and it's a pity things have turned out this way. It's hard to believe that Steve died from a stingray barb eight years ago on Queensland's Batt Reef.