I have a rugby-obsessed grandson, too, aged 12. He lives in England but was born in Wales and feels Welsh, so he has a real problem when Wales play England. In Wales, this particular rivalry takes on an importance somewhere between a war and a religion! This song from Max Boyce sums it up.
We paid our weekly shilling for that January trip
A long weekend in London, aye, without a bit of kip
There's a seat reserved for beer by the boys from Abercarn
There's beer, pontoon, crisps and fags and a croakin 'Calon Lan'.
And we were singing hymns and arias, 'Land of my Fathers', 'Ar hyd y nos'.
Into Paddington we did roll with an empty crate of ale
Will had lost at cards and now his Western Mail's for sale
But Will is very happy though his money all has gone
He swapped five photos of his wife for one of Barry John!
And we were singing hymns and arias, 'Land of my Fathers', 'Ar hyd y nos.'
We told the guard that we're from Wales, and asked 'Is Twickers far?'
He said "Man you can catch a 48, but it isn't very far."
On the bus were boys from Blaina who'd been to see the Queen
So we had a quick Gymanfa, aye, it was the greatest London's seen.
'cause we were singing hymns and arias, 'Land of my Fathers', 'Ar hyd y nos'.
We got to Twickers early and were jostled in the crowd
Planted leeks and dragons, looked for toilets all around
So many there we couldn't budge -twisted legs and pale
I'm ashamed we used a bottle that once held bitter ale!
And we were singing hymns and arias, 'Land of my Fathers', 'Ar hyd y nos.'
Wales defeated England in a fast and open game
We sang 'Cwm Rhondda' and 'Delilah' damn, they sounded both the same
We sympathised with an Englishman whose team was doomed to fail
So we gave him that old bottle, that once held bitter ale!
He started singing hymns and arias, 'Land of my Fathers', 'Ar hyd y nos'.
There is a bit more, but it is not very politically correct! The Welsh adore that song.