noun, noun or participle which takes 'suru', intransitive verb, noun which may take the genitive case particle 'no'
promiscuity; group sex
Refers to sexual activity involving multiple partners, often in an indiscriminate or group setting. Can be used as a noun, with する for the action, or as a no-adjective.
そのパーティーは乱交に発展した。
The party turned into an orgy.
乱交パーティーは法律で禁
Group sex parties are illegal in some countries.