Black Butler Kuroshitsuji

https://www.fanfiction.net/s/9174794/2/

Sebastian and Ciel's relationship has changed after their contract ended. Ciel is no longer serving the queen, but like always he's managing his business under Sebastian's supervision. I suck at summarising so I'll stop there. You can't judge a fanfic by its description, though it gives you an idea on how screwed up it's going to be.