They never had a physical relationship. Asami was his Boss. Asami never stoked Sudou's fire. Sudou built it up in his own head.
To me it seems Sudou worked for him and then got infatued to the point of wanting to kill Akihito, but nothing more than that. They don't seem really close.
there was never a relationship between Asami and Sudou, physical or personal. The only thing they ever talked abut was work. Sudoh went loopy and thought if I get rid of Takaba , I can have Asami for myself. Asami is to good looking for his own good. his sweet smell is driving everybody crazy in Yaio land. that's it Asami drove Sudou crazy. The Seme of Seme curse struck.
Asami didn't love Sudoh, Sudoh was just obsessed with Asami. It was totally one sided.
I kept on re-reading but I don't understand the relationship asami have for sudou. Do they have a physical relationship? Do asami loved him?