Noun- A human homosexual male's anus that is frequently penetrated and enjoyed by another gay man's penis. In male homosexual couples, the anus of the "receiver."
"Franz have you been cheating, your dick smells like another man's buttpussy?"
Person 1: That Kristen Smith girl is a real buttpuss.
Person 2: Ya she is a buttpuss, but is unaware of it.
Person 1: They never are aware that they are a buttpuss.