Read "Amor Aeternalis" at The Eldritch Dark:
The title of this sonnet from Clark Ashton Smith (CAS) is Latin for "eternal love". Although these lines certainly express a bitter tone, it's hard not to enjoy the pure poetry at work here, especially in the closing sestet:
Away! I know the weariness and fever
Kisses compounded of the world's old dust
With fire that feeds the seventh hell for ever!
The grave shall keep a gentler couch than thine,
Though round my heart the roots of nettles twine,
Wreathed in the ancient attitude of lust.
If there was ever a true poetry that emerged from the end of a relationship gone wrong, this work is certainly it!