There's a late 17th century broadside song, The young-man's lamentation, that ends

Tho' I am forsaken,
yet she is forsworn,
Yet she is mistaken
if she think that I'll mourn,
I'll set as slightly by her,
as e'er she did me,
And for ever will deny her,
let her go, farewel she.

It begins

Meeting's a pleasure,
but parting's a grief,
An Unconstant lover
is worse than a Thief;
A Theif he can Rob me,
and take what I have,
but an Unconstant Lover
will bring me to the grave.


Early examples of two much-travelled floaters. You can see an image at Bodleian Library Broadside Ballads, but it's largely illegible.

The young-mans lamentation