Cousin zone

Similar to friend zone, one may find themselves in this dire predicament when a flirtatious attempt with another is ended abruptly due to them exclaiming something along the lines of 'but we're cousins!' or 'you're my cousin!'.

(After yearly family gathering)
Cletus: Goddam it Travis, it was going real gooood
Travis: Why, she didn't cousin zone you did she?
Cletus: You're darn right she did