Echoing EmmaB:
Don't go out with Jane no more
Don't go out with Mary
Don't go out with girls any more
Woops! I am a fairy.

I recall as:
"I don't go with girls any more,
I don't go with Mary.
I don't go with girls anymore.
Whoops, I'm a fairy"
The tune (not "the girl I left behind me") was "Pop goes the weasel"
This would be late 60s/early 70s UK