People are always asking me whether Tells of Sad is slash, or pre-slash, or whether it will end slashy. I've answered this question a million times, but I'll just put this out there for the record: it's gen. It was always meant to be gen. But look at the title. This is about the close relationship between two brothers. That's what it's about. It's about how co-dependent they are, and you can read that as psychotic, as irrational, or erotic. Any one of them, you can read it that way.
In Vulcan, the term t'hy'la can mean brother or lover. There's a reason for that: it's because what you feel for kin is very close and connected to what you feel for someone you love romantically, especially in long term romances. Sex is a very big, important thing and it colors a lot of feelings. And typically the relationship of kinship does not have that. I am not discounting the importance of sex. But sometimes, people make a bigger deal out of sex than there needs to be. They draw a great big fat line between sex and love, and the sexual feelings you feel and the loving ones you feel. And sometimes it's not so clean cut.
So no, Tells of Sad is not slash. But I understand how people might read it that way. I've left a lot ambiguous in Tells of Sad, because Sam and Dean are really fucked up, okay?