Fans were quick to jump on the bandwagon and wished Terri a happy ‘unbirthday’ too. One fan commented, “Happy half birthday, Terri!,” while another said, “I love this. I’m doing this from now on!! Happy unbirthday Terri!”
However, in the comments section, many also pointed out that Bindi’s wearing a heart-warming necklace in the photo: a pendant with a picture of her late dad, Steve Irwin, on it.
WATCH: Bindi Irwin's daughter recognises Steve Irwin
“That necklace 😭,” one fan commented. Another asked, “Where did you get that necklace made? 😍 So lovely.”
This is the first time Bindi has ever posted an ‘unbirthday’ tribute on social media; although she’s no stranger to posting traditional birthday tributes.
Last year in February, Bindi posted an extremely touching birthday post on what would have been Steve’s 60th birthday.
“Happy Birthday to the greatest dad and Wildlife Warrior. Today I'll watch 'The Crocodile Hunter' with Grace Warrior and share stories about her incredible Grandpa Crocodile. I love you with all my heart. Your legacy lives on,” Bindi wrote alongside a throwback photo of her and her late dad.