Terri Irwin is remembering her late husband on the day they decided to spend forever together.
On Sunday, the wife of late Crocodile Hunter and animal activist Steve Irwin shared a sweet photo and tribute, commemorating the anniversary of their engagement.
“It was 28 years ago today, here at @AustraliaZoo, that Steve asked me to marry him,“ Terri, 55, wrote on Twitter. “Life is constantly changing. Love is forever.“
Terri and Steve first met back in 1991, when Terri stopped by at a small reptile park in Australia where Steve had been working as a zookeeper at the time. The sparks were immediate, she recalled to PEOPLE last year.
“Right away we were talking about wildlife, and our passions in life and I kept thinking, ‘I wonder if this guy’s married,’ ” she told PEOPLE. “He said to me, ‘Would you like to meet my girlfriend, Sue?’ I tried to be cool about it, but I was devastated. Then he goes, ‘Hey Sue, Suey, come here.’ And his little dog came running around the corner. ‘This is my girlfriend, Sue,’ he said. I thought, ‘Yes!’ “
While the two had an instant connection, Terri had to return home to Oregon and remembered Steve telling her they would stay in touch.
“He said, ‘We’ll have to keep in touch,’ but then a week went by and he hadn’t called, and two and three,” she recalled. “I thought maybe I misunderstood what I thought the connection was.”
Finally, after a month, he called and said, “I’m coming to Oregon to see you.”
In 2006, the legendary wildlife expert was working on the documentary series Ocean’s Deadliest when he was attacked by a stingray off the coast of northern Australia. Irwin died at age 44 on Sept. 4, 2006.
Every year on Nov. 15, Steve’s family celebrates his legacy on Steve Irwin Day, the annual international event honoring the life and legacy of the beloved Animal Planet star.
“Dad was my hero and the greatest Wildlife Warrior,” Bindi, 21, told PEOPLE last year. “It’s a blessing to continue his work with my amazing family. We hope to make him proud every day. We are celebrating with lots of khaki and animals! Khaki’s not just a color, it’s an attitude!”
Her brother Robert, 16, also called Steve Irwin Day “one of the most special days of the year for our family.“
“Dad was the ultimate Wildlife Warrior and so ahead of his time — discussing climate change, habitat destruction and so many other environmental issues before they were as widely discussed as they are now,” he said. “He changed the world and so many lives across the globe. For my family and me, we miss him every day, but are proud to keep his mission alive. It’s wonderful to see so many people showing their support for his legacy.”