Posting on Instagram, he shared a sweet throwback picture of the two siblings holding a snake at Australia Zoo.
“Happy #NationalSiblingsDay to the absolute best,” he wrote on his post. Bindi was quick to reply, commenting “Love you so much!”.
Fans were quick to gush over the cute picture, with one writing, “Look at those precious little inquisitive faces. What amazing, capable and inspirational adults you have grown into”.
Not to be outdone, Bindi also posted her own tribute to Robert on her Instagram with a snap of the pair posing next to photos of themselves as kids.
In her caption she wrote, “Happy #NationalSiblingsDay to the very best. Love you 3,000!”
The pair are very close and frequently post about each other on social media. Robert is particularly proud of Bindi’s daughter Grace who recently turned one.
Bindi and her partner Chandler Powell were lucky enough to celebrate Grace’s first birthday at Australia Zoo with their extended family, including Chandler’s parents and Robert.
Robert celebrated Grace on social media, writing, “Happy Birthday to my favourite little human in the world. Love you so much Grace, I’m the luckiest uncle ever!”.
Bindi also posted a sweet tribute to Grace, adding, "Happy Birthday to my graceful warrior. One year of watching your beautiful heart bloom into the most extraordinary person.
"Grace, you have been an old soul from the very beginning. It is the greatest blessing to be your mama. I love you eternally, unconditionally and infinitely."
It has been almost 16 years since Steve Irwin tragically passed away after being stabbed by a stingray in Queensland.
Robert has since stepped into his dad's shoes, working with crocodiles at Australia Zoo since the age of 10. He recently posted a photograph of himself feeding the crocodiles, and fans couldn’t believe how similar he looked to Steve.
“I had to zoom in. Thought this was your dad Steve!” one fan wrote.
“An entire generation that your dad taught about wildlife is watching you step into those shoes and fill them just as good as he did. It’s something special,” another added.
“He is definitely his father's son. Wow!”
“Incredible! Steve would be proud!”
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