Explain a pig joke. What is funny here?

Question

The joke is: "Yesterday a pig invited me to see his new home. Actually it was quite stylish." How should one understand this? It does't seem funny at all.

Answer 1

Pigs live in a sty:

a pen or enclosure for swine; pigpen.

^{dictionary.com}

The joke is using "stylish" to mean "like a sty". It is a pun on the normal meaning of stylish:

characterized by or conforming to style or the fashionable standard; fashionably elegant; smart or chic

^{dictionary.com}