Jonathan Davies has shared baths, bedtimes, breakfasts and the Scarlets dressing room with brother James – but never a Test match until today.
When the two sons of Bancyfelin run out to face England at the Principality Stadium this afternoon, it will be the first time they have worn a Wales shirt together on the same pitch.
In doing so, they become the first brothers to play together for Wales since the Robinsons – Jamie and Nicky – in 2006 and the first Scarlets or Llanelli pair to do so while together at the same club.
But while Jonathan will be winning his 81st Test cap for Wales and the Lions in the centre, flanker James will be earning only his fourth.
It has been a long road for the younger Davies, who is now 28 – three years younger than Jonathan – but miles behind in terms of international experience.
Even a fourth cap looked a very distant prospect – and a trip to the World Cup extremely remote – just a few months ago as injuries piled up once more for the openside.
Aside from their parents no-one will be more proud to see James back on the pitch for Wales than Jonathan, who says: “He’s worked hard over the summer. He’s always given a good account of himself and I’m sure he’ll do that on Saturday.
“Injuries are part and parcel of professional sport, unfortunately. Using the drive and hunger to want to get back to the top level helps everyone get over these injuries.
“He’s worked hard over the summer and he’s got the chance he deserves. He’s alright and he can handle himself, to be honest. It’s great news for him and I’m looking forward to seeing how he goes.”
Jonathan admits than during all those back garden contests, the squabbles over bragging rights, and the imaginary future contests, he never really believed they would share a Wales match.
“No if I am honest. It’s something I’m sure when we look back on we’ll be very proud. I’ve got a better record in the garden than him! It’s interesting to play with my brother for Wales but I can’t share a room with him!
“He lived in my flat a few years ago and it was awful! He’s very messy!
“Mum and dad and my sister will be very proud as well. But, look – we’re preparing to hopefully go to a World Cup and we’re not going to sugar-coat it at all this weekend.
“We want to go out there and give a great account of ourselves and warrant a seat on the plane to Japan.”
Business first, then – and family later.
“We want to win every game we play but the most important thing for us is to make sure that the players who make the plane to Japan are in the best place possible.
“We don’t want to win every game in August and then lose games in the World Cup. But we need to make sure we perform better this weekend.”
Wales will make a first Principality Stadium appearance since March, when a 25-7 victory over Ireland secured the Six Nations title and Grand Slam glory.
A win at England’s expense this weekend would make it 11 in a row against all opponents and also see Wales replace New Zealand as world rugby’s number one-ranked nation.
Wales have never previously reached the rankings summit, and it would represent an impressive feat, especially just a month before the World Cup starts.
“It’s nice to be home,” said Wales captain Alun Wyn Jones.
“The occasion when we were here last time was obviously special, and we are not going to lie, we want to carry that on.
“There is a big responsibility when we pull the jersey on. I say it a lot, and pardon the cliche, but it means a lot to be here and playing at home.”
Wales, though, will need to show an improvement from last Sunday’s outing at Twickenham, when England beat them 33-19.
“Results are important off the back of a performance – your performance tells you a lot about your result as well,” Jones added.
“You play games sometimes where you might not play great, but you still win. That wasn’t the fact on the weekend.
“We were slow out of the blocks, and we have got another opportunity to put that right. It is an opportunity for us to redeem ourselves after the first game.
“It would be very easy for us to say we were rusty (last week) because it was our first warm-up. We can’t drop our standards or allow our perception to change because of that. We pull on a Test jersey for a Test match.
“We realise where we have got to pick up, and there is an opportunity for people that played and a few guys coming in.”
Jones, meanwhile, believes that flanker James Davies has an opportunity to continue his “stellar form” when he faces England.
Davies joins fly-half Dan Biggar and lock Jake Ball as changes following events in south-west London six days ago.
I thought he sent a flare up in Argentina to say he’d arrived,” Jones added.
“He’s had injury struggles since, but he’s got an opportunity at the weekend to continue the stellar form he has shown for long periods in the Scarlets jersey.
“Obviously, there is a bit of pedigree there with his brother in the centre.
“James has been a stand-out in what has been a hotly-contested position in Wales for a long time. He’s been very close and has got the nod after banging on the door.”
Wales: L Williams; North, Jonathan Davies, Parkes, Adams; Biggar, G Davies; Smith, Owens, Francis, Ball, AW Jones, Wainwright, James Davies, Moriarty.
Replacements: Dee, W Jones, Lewis, Shingler, Navidi, A Davies, Evans, Watkin.
England: Daly; McConnochie, Joseph, Francis, Cokanasiga; Ford, Heinz; Genge, Cowan-Dickie, Cole, Launchbury, Itoje, Lawes, Ludlam, B Vunipola.
Replacements: George, Marler, Sinckler, Kruis, Singleton, Youngs, Farrell, Tuilagi