Princetompax 5th Sept - I heard this from a fellow pupil (girl) at Bell-Baxter Secondary (Cupar Fife) around 1947. Thus:

After the ball was over
Johnny took me for a walk,
He took me behind some bushes
And said let's have a talk;
He pulled oput a hairy monster
And put it between my thighs,
I said oh no John don't
Or you'll make my belly rise.