According to the late Tony Rose (whose version of the song was rather fine), the payment in the earlier verse was the result of a misunderstanding. He said the girl's mother had explained that under such circumstances, money should change hands. The girl just made a mistake about who was supposed to hand it over.
As for it's being reprehensible, I think the sailor behaves much better in the whole song than the soldier in "Sweet Nightingale" or the Scottish prisoner in "The Fair Flower of Northumberland".