Belinda's version is the version I was introduced to by my grandfather many years ago. Except for slight changes in the second and in the last verse:

The second verse began:

Now, nearby this maiden her lover did dwell.

the final verse ends:

Said he: "Now I die if I stay, it is true."
He said, "Now I fly and he flew up the flue."

I believe this means that there were two different speakers, the first line was the ruffian and the second was the father. As a poet, I always look for the metaphor or simile in the lyrics. As near as I can figure, "Now I fly" is a reference to earlier in the song when the ruffian asked the maiden to "..Fly by the light of yon star." So, in my estimation flying was sexually related. So to fly up the flue is to do something sexual with an exhaust pipe. I believe this was the intent of the writer, but I could be looking too hard. Apologies for being indiscreet.