For nineweaving, on the train

[shewhomust]

The version I know - and I've googled about a bit, but no-one else seems to have exactly the same thing, although several have many more verses - goes like so (to a tune I know only as Humoresque, but you probably knew that):

Please refrain from urination
While the train is in the station -
Have regard for railway property;
If you want to pass some water
Go and ask the railway-porter
He will show you the lavatory

Honeymooners in the carriage
Please don't consummate your marriage
While the train is standing in at Crewe.
Don't perform your natural function
Till you get to Clapham Junction
Where there's really bugger all else to do.

Bonne route!