Casper Ruud was smiling during his United Cup press conference on Monday evening in Sydney, but it was not just because Norway defeated Croatia 2-1.

As the action was unfolding inside Ken Rosewall Arena, Ruud’s sister Charlotte and cousin Josefine created a viral moment. They were walking in a tunnel to the court when they began strutting a runway walk. Little did the girls know a camera was following their every step.

When they realised, their embarrassed reaction was memorable.

“They're not typically too shy in front of the camera. They like to be around the tournaments and show up, like to sit in the box. That's their favourite thing to do. They were courtside with us,” Ruud said. “This is not typical for them to do these things. I think they were a bit embarrassed. I saw them. They were blushing and all red in their faces.

“It was a good kind of learning experience for them to say that they can't do anything they want at all times.”

While the girls are not competitors for Norway, they play tennis and Ruud is happy to have them partake in the United Cup experience.

“They're here not playing the tournament, but practising hard. They're going to both go to college after next summer,” Ruud said. “It was sort of the last chance for them to go to Australia. They're here and will come to Melbourne, as well.”

It is safe to say they will leave Australia with an unforgettable memory.