悪わるい虫むし

noun

undesirable lover; bad boyfriend/girlfriend

Idiomatic expression for a romantic partner one's family or friends disapprove of; often used in the phrase 悪い虫がつく (to get involved with a bad lover).

• 娘むすめに悪わるい虫むしがつかないか心しん配ぱいだ。

  I'm worried that my daughter might get involved with an undesirable lover.

noun

passion; temper; irritability

Refers to a fit of anger or strong emotion; often used in the phrase 悪い虫が起こる (to get into a temper). Somewhat dated or literary.

• 彼かれは急きゅうに悪わるい虫むしが起おこったように怒おこり出だした。

  He suddenly flew into a rage as if seized by a fit of temper.