「好色と倒錯の違いとは？」「好色なら羽を使うが、倒錯なら鶏をまるごと使う」

「？」「、」

'What's the difference between licentiousness and perversion?' 'The licentious use a feather; the perverted use the whole chicken.'

Literal

''Licentiousness [and-と] perversion [possessive-の] difference [topic-とは]?'' ''Licentious [if-なら] feather [object-を] use-[but-が], perversion [if-なら] chicken [object-を] whole use.''

A classic risqué joke, widely cited in Japanese comedy. 好色 ('licentious, sensual') and 倒錯 ('perversion, inversion') are both formal words, which makes the juxtaposition with the literal chicken imagery funnier. The ~なら conditional sets up each case. The joke hinges on the contrast between subtle sensuality (a single feather) and over-the-top perversion (deploying the entire bird).