More examples, some of them very clever:

Of Treason
Treason doth never prosper; what's the reason?
For if it prosper, none dare call it treason.
-- Sir John Harrington (1618)

Epigram Engraved on the Collar of a Dog Which I Gave to His Royal Highness
I am his Highness' dog at Kew;
Pray tell me sir, whose dog are you?
-- Alexander Pope (1738)

Their relationship consisted
In discussing if it existed.
-- Thom Gunn (1992)

I'm tired of Love: I'm still more tired of Rhyme.
But Money gives me pleasure all the time.
-- Hilaire Belloc (1923)

Variation on Belloc's "Fatigue"
I hardly ever tire of love or rhyme --
That's why I'm poor and have a rotten time.
-- Wendy Cope (1992)