I'm really sorry to bother - some time ago my laptop was stolen, and I'm trying to find again the fics I had bookmarked. (Now I have discovered Delicious...)
I have this vague memory of a fic in which something was happening between Tsuzuki and Hisoka, and then... I guess Hisoka had second thoughts or similar, and the scene I remember is Tsuzuki getting angry and saying something along the lines of, 'I'm not Muraki. You don't get to make me feel like him.' That was the gist anyway.
Thank you very much for your help!
(Also, any lengthy fic that deals with their get-together - well developed, not just 'I love you!' 'Ok let's have sex now' kinda thing - is extremely welcome :)