Euphemism, intended to obscure:

"Young man, despair,
Likewise go to,
Yum-Yum the fair
You must not woo.
It will not do,
I'm sorry for you,
You very imperfect ablutioner!"
-- Pooh-Bah, in The Mikado, Act I

Translation: You stink! (Or at the very least -- you need a bath...)

Ernest Bramah, in his Kai Lung books, sparkles with many more of these. And he makes you think they're compliments. Until you decipher them...