also: バターいぬ
noun
man who performs cunnilingus
Vulgar slang; refers to a man who engages in oral sex on a woman, likened to a dog licking butter.
あの男はバター犬だって噂だよ。
Rumor has it that guy is a butter dog.
noun
dog that licks butter off a person's body for sexual arousal
Vulgar slang; describes a dog trained or used to lick butter or other substances from a person's body as a sexual act.
バター犬の動画がネットに出回っているらしい。
Apparently videos of butter dogs are circulating online.