Or you could try an alternative ending (originally written by Julian Flood and posted to uk.music.folk, slightly adapted by me):

So off to the doctor go, hey ding a dorrity,
Off to the doctor go, me being young;
Off to the doctor go, tell him your tale of woe,
Maids when you're young, never wed an old man.

Now he's got Viagra, hey ding a dorrity,
He's got Viagra, me being young;
When he takes Viag-a-ra he comes like Niagara,
Maids when you're you CAN wed an old man.