Family Zone
The family zone is similar to the friend zone in that it puts you in a position where a partner isn't interested in romantic interaction because of your role in their life. Being in the family zone means that the person doesn't want to sleep with you because you are a blood relative (like a brother or a daughter).
Meanwhile in Alabama...
Sister: Ew you're disgusting! Just because I've slept with every other guy in school doesn't mean I'm going anywhere near you! Perv!

Brother: Wow seriously, how you just gonna stick me in the family zone like that? Thought we had chemistry n shit.

Sister: Ew no! You're my brother!