cooplaine
The romantic relationship between Blaine Anderson and Cooper Anderson from the TV show Glee, also known as andercest. Probably canon at some point, they most likely fooled around before Blaine met Kurt, his boyfriend (and after, who are we kidding?)
Kurt: Is my boyfriend singing a break-up song with his brother?
Yes, Kurt, he is. Cooplaine.
Yes, Kurt, he is. Cooplaine.