Non-YA books with masculine gay male leads, NOT primarily focused on romance/LGBT themes?

Title. I have a few LGBT-related narrative titles in my TBR list, but I really just want to read something exciting with a main character that happens to be a cool gay guy. That's not to say he can't be outwardly romantic/sexual/etc. (bonus points if he has a healthy non-tragic relationship), but I'd prefer if the story was driven by something that wasn't explicitly related to the gay experience.

For reference, I've just started reading again after a long absence, and I've enjoyed works by Stephen King and Elmore Leonard as of late, so something in a crime, thriller, or horror vein would be nice. Sci-fi/fantasy is fine, but not preferred. I'd also prefer works by gay male authors if possible, though that's not a requirement.