Bindi Irwin has shared the "defining moment" in her relationship. And it's a little unusual.

Bindi Irwin has always been a tad precocious. She was on TV from the age of two, had her own show at nine and has been cavorting with wild animals since she could walk.

Now, at the ripe old age of 18, Bindi Irwin has already found her “soulmate”.

In their first joint television interview, the Wildlife Warrior and her partner, US wakeboarder Chandler Powell, told Entertainment Tonight about their young love, including the biggest step in their relationship so far: the moment Chandler slipped into a set of khakis.

“It’s this really big thing for me,” Irwin said. “It was kind of one of those moments that was a real defining moment for me, because you know, it’s only the people who are the closest to us that get their khakis.”

The couple met more than three years ago, when Powell, now 19, and his family visited Australia Zoo.

“He sent a letter asking my mum asking if he could stay in contact with me,” Bindi told the programme.

Powell added, “After I met her I thought ‘I really want to stay in touch, but I don’t want to come across wrong, or anything like that. I think this is the best way to handle it. I’m going to give it a go.'”

“And that was that,” said Bindi.

Chandler becoming a card-carrying member of the Irwin family. Image: Instagram.

After slogging through a "challenging" long-distance relationship, Chandler eventually moved to Queensland and took up a job alongside Bindi at Australia Zoo.

But despite the recurring headlines and tabloid speculation, that's as serious as things will get for now.

"I mean, we met three years ago now and people are always wondering whether we're engaged or married," she said.

"No marriage in the, kinda, 'right now' – that's years and years away."

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