Eddie Jones and Michael Cheika's shared history often dominates England-Australia weeks but in Sunday's Twickenham clash there'll be another even closer tie on the sidelines.
Wallabies defence coach Nathan Grey and England attack coach Scott Wisemantel are long-time friends, going back to when Wisemantel coached Grey at the Waratahs in 2000-01.
The Aussie on the English staff is a godfather to Grey's son Toby but their friendship will be put on hold this weekend when Wisemantel's English attack will attempt to cut up the Wallabies defence, which is run by Grey.
“He actually coached me when I first came to the Waratahs,” he said.
“A very good family friend, our families are very good friends and he's the godfather of my son.
“Obviously have a really close relationship with Wisey and Gab his lovely wife, so yeah it's going to be interesting.
“We'll see each other out on the pitch. I see he's running the water so we'll probably be tripping each other up and having a bit of friendly banter out there at Twickenham so yeah it'll be fun.”
Before taking up the England job, Wisemantel had kept in touch with Australian rugby, working with the Classic Wallabies in Australian rugby last year and coaching a Wallaby XV in France in 2016.
Grey said he had tried to start up some banter with Wisemantel this week but it was radio silence from Pennyhill Park.
"I sent him a text message asking him if they're going to run that 13-man lineout again and I haven't got any response," he laughed.
"No doubt I'll look forward to having a chat probably before the game and definitely having a beer after."
The expat frostiness extended further than Wisemantel's phone, though, it seems.
Former Wallabies winger David Campese publicly sledged his ex-Randwick teammate Eddie Jones on Twitter for not turning up to a function at Australia house. He later deleted the tweet.
Grey will enter the Twickenham clash with more confidence than a few weeks ago after significant improvements in the Aussie defence in the past two Tests, where they kept both Wales and Italy under ten points.
But England will present a more complex picture.
“Like all things in rugby, there's lots of little components that go into things being well and being able to execute well,” he said.
“The guys having the confidence in each other on the field and then backing themselves to do that and then that intent to want to get in the line and get up and get forward and stay connected is something we're always working on and it sounds, it is quite simple, but it's hard to execute consistently well and the guys have been doing that so they should be commended for it, yeah.
That they have those two performances under their belts now can only help them at Twickenham, though, Grey said.
“We've been trying to hit our markers around what we want to do defensively and forcing turnovers and putting an opposition under pressure and being able to turn that pressure into points and possession of which we've been able to do a few times,” he said.
“That's the real pleasing thing, that the guys are seeing the reward from the work that they're doing and that manifests itself on the field in pressure and forcing the opposition, forcing their skill to be executed under pressure and forcing errors and basically allowing us to get the ball back.”
The Wallabies desperately need a win from this final game of 2018 after just four wins this season and they'll be looking to break a five-match losing streak against England.
Their lean season has been a source of frustration among fans in Australia but there was commentary from across the ditch this week that the Wallabies' lean year had damaged the All Blacks by not preparing them well enough for sterner rivals.
One New Zealand columnist wrote the Wallabies' disappointing Bledisloe results had softened the All Blacks up for a loss to Ireland in November.
It's a suggestion Grey dismissed in London..
“We’ve beaten them a couple of times in the last couple of years so yeah, it’s great for Ireland to get their first win at home against them,” he said.
“I think New Zealand have been consistent over a long period of time. You’ve got to look at the big picture and identify that the top six, seven nations in the world at the moment, if you’re not on your game you’re going to get beaten.
“There’s opportunities to beat any team in the world at the moment. You’ve just got to make sure it’s the team that’s going to be the most consistent in delivering how they play because if you’re off you’re going to lose and we’ve shown that against New Zealand a number of times.
“Other teams have against them as well. Super happy for Ireland to get that win.”