Jack overhears a girl tell her lover that she will lower a string from her window to let him find her. Jack comes to her window early and enjoys the girl's charms until morning when she realizes the truth. Having had his romp, he returns gaily to his ship
In several versions, including [the Penguin text and the Copper text], the story ends: Jack offers to steal away quietly; the lady tells him not to stray too far for "I never will part from my jolly Jack Tar." - PJS
The first instance of this motif in English-language folklore appears to go back to none other than Shakespeare: according to a story in the diary of John Manningham, it came during a performance of Richard III.
A lady in the audience sent a note to Richard Burbage, who played Richard, inviting him to her bed. Shakespeare got wind of it, and he, rather than Burbage, enjoyed her charms. When Burbage arrived, Shakespeare allegedly said, "William the Conqueror was before Richard III."
Hey, I didn't say I believed it.
The notes in Flanders connect this with "Glasgerion" (Child 67).All we can say is, the theme is somewhat similar, but they're differentsongs.- RBW