Just to emphasise the 'piss take' aspect here is David (Mick) Robbie's version. He was also in the Navy just after WWII. Recorded 1971 (The previous one was recorded 1967)

On the jetty stood a mat'lot in his uniform so neat,
He's waiting for the picket boat to take him to the fleet,
And there upon the quayside stands our hero's fiancé
And as the crewmen row him out they hear our hero say

You'll be happy l s I t s
For you those wedding bells will surely ring
And when England's shores are sighted, two hearts will be united
You'll .....

Now that ship went into action on that cold December morn
The sailor boys were fighting for the place where they were born
And amongst the dead and dying our gallant hero lay
And as they carried him below his shipmates heard him say

Please don't burn our shithouse down
Mother has promised to pay
father dear's in the ocean deep
Kate's in the family way
Brother Bill's got gonorreah
And times are looking bad
So please don't burn our shithouse down
Or we'll all have to shit in the yard.


I too would dearly like to see some evidence that the song is older than WWII.

There are other RN versions in Cyril Tawney's Grey Funnel Line p133, just the chorus in Martin Page's 'The Songs and Ballads of WWII' p25.
I know of no other sources earlier than these. I'll have a quick look at Roud. It may throw something else up.