The fall-outs? They were epic.
Sika Manu, the Hull FC forward, was desperate to win and – when he didn’t – he would sulk.
Refuse to speak.
“And mate, that was just playing Fifa on the PlayStation,” smiled Willie Isa, the Wigan forward.
The pair lived together for two years when they were team-mates at Melbourne Storm earlier in their careers.
“So I’d cook a meal for him, cheer him up.
“Then he’d put the boxing game on, and he’d always win at that.... then I’d throw a sook and not speak to anyone after!
“You could tell even from playing PlayStation, we were two competitive blokes.”
Fast-forward eight years, and the former house-mates will be on opposite sides when Hull FC and Wigan collide at Wembley this weekend.
At 28, Isa can be considered a veteran of the game, but he has never forgotten the help and support Manu gave him when he left his family home near Sydney and made the move to Melbourne.
“I was only a young lad coming through and I always watched what he did, and I always tried to take bits of his game into mine,” he recalls.
“But the main thing was how he helped me settle in. It was a big move for me at the time, and it was good to have someone there.
“I cooked for him, he wasn’t the best at that – everything else around the house, he was fine with – but I did the cooking.
“And look at him, he’s a big boy... I helped him get there!
“But he really looked after me, and I’ll always be grateful to him and his family.
“I’ll tell anyone, he’s an older brother to me.”
Which is why, should they come into direct contact on the hallowed Wembley turf, they will rip into each other like good siblings do in rugby league!
“Whenever we play, he doesn’t back down, and I’m the same,” he said. “It’s like little brother-older brother... the harder you go, the more your older brother will respect you.
“It’ll be a good one, it’ll be interesting. He’s settled in Hull FC and he’s been playing pretty well.
“We always leave it on the field. After the game, we’re always good with each other.”
Shaun Wane has hinted Isa will keep his place in the side, despite the return to fitness of Joel Tomkins.
The former Castleford and Widnes forward missed out on the World Club Challenge – a decision Wane admits was one of the toughest of his career.
“Because it was nothing to do with performance, I just decided to go with a bigger bench,” he explained. “But telling Willie... it was one of the hardest chats I’ve had.”
Isa, now in his sixth season in Super League, admits he didn’t know the esteem in which the Challenge Cup is help when he arrived in England.
A fan-club of family members and close friends are staying up late to cheer him on from in front of their TV screens in Australia.
“You hear other people’s stories, leading up to the game and the Wembley week and the games, and I want to create my own story,” he added.
Elsewhere, winger Tom Davies is set to earn a recall after missing the game against Salford with a hamstring strain, leaving only long-term casualties Ben Flower, Morgan Escare and Dom Manfredi on the injury list.