the way i learned it was:

Hi!
my name is joe
and i work in a button factory
i got a wife and no kids
one day my boss came up to me and said joe
are you busy i said no!
he said push this button with your left hand
so i did.....

It carries on so after pushing with the left hand it goes
i got a wife and one kid and when he finally goes thru the whole song (right hand, left leg, right leg, bum, nose, head etc) you go to the last verse....

....are you busy i said
YES!!

its a great song, i learned it in girl guides. we used to have competitions to see who could sing it the fastest!!