A term used by band geeks to describe somebody who dates people only in their section. It's highly frowned upon, especially since sections are family. And things can get awkward when you break up and have to deal with them still.
Matt: Did you hear that Ashley, the french horn player, is dating Tyler?
Preston: Aren't they in the same section?
Matt: Yeah they are. What homosectionals.
Jim: I'm heterosectional
, what about you?
Jake: Nah, man, I'm homosectional. The girls in my section are hot.