Wartime R.A.F.

Arseholes are cheap today
Cheaper than yesterday
Little boys are half a crown
Standing up or lying down.
Bigger boys are two and six
Larger ones are three and six
For they know better tricks
And one at five bob.

Some are wreathed in smiles
Others are sore with piles
The one for me
Is the one that's free.
Tally ho! tally ho!
What a lovely sight
Half a mo, half a mo,
While I have a shite!

(Well you asked!) Lots of variations.