25/07/2017 3:52 PM AEST | Updated 25/07/2017 4:45 PM AEST

Australia's Clingiest, Cuddliest Kangaroo Is Now A Feisty Teenager Who Just Wants To Box

Why do they have to grow up?

The Kangaroo Sanctuary, Alice Springs

It's a bittersweet truth every parent understands only too well. No matter what you do, you just can't stop them growing up.

With a hint of a sigh but an undertone of pride, Tahnee Passmore-Barns of The Kangaroo Sanctuary in Alice Springs, Central Australia, tells how Johanssen -- the cuddlesome red kangaroo who captured the world's heart -- is now a young adult male who has largely abandoned his clingy ways.

Johanssen was a young joey who had been orphaned when he was taken in by The Kangaroo Sanctuary. Immediately he latched onto Passmore-Barns' husband Chris (who goes by the name "Brolga"). The video of Brolga and Johanssen together went viral, and The Kangaroo Sanctuary re-posted it this week.

In the video, Brolga tries to break free of young Johanssen's grip saying "I'm coming back, I'm coming back", while the needy young roo refuses to let go.

"Johanssen thought Brolga was his mother," Passmore-Barns said of the video. "He still does."

Uh, so you're the father?

"Right. I'm the dad."

Which is not something every woman gets to be, but there you have it.

The Kangaroo Sanctuary Alice Springs
Johanssen on July 25, 2017.

"Johanssen is fairly big now. He is a young adult male and is doing really well," Passmore-Barns said of her marsupial "son", who is two-years-old in human years but a teenager on a kangaroo timeframe.

"He doesn't cuddle as much as he used to. When he was young he just cuddled a lot. Each kangaroo is different."

The Kangaroo Sanctuary, Alice Springs
A still from the viral video in which Johanssen got all adorably panicky at the prospect of Brolga leaving him.

Johanssen is so named because he spent his early days alongside a young female roo named Scarlett. (Yes, we know he should be spelled Johansson, but kangaroos are not great spellers). He now prefers the company of his own sex and has taken up every male roo's pet sport -- boxing.

"He's made lots of friends at the sanctuary and he's practicing his boxing skills. He's a real teenager."

As for whether he's set to take on the sanctuary's Alpha male Roger (pictured below) in a 12-round heavyweight contest, well, we're not quite sure he's ready yet.

The Kangaroo Sanctuary rescues orphaned roos in Central Australia. To donate, click here.