Just leaving a summary for myself to remember the story after I've let it accumulate more chapters. Please ignore.
Spoiler!
Two roommates. Blonde one has reputation for lending people money and being loan sharky. Brown haired one was desperate and borrows money, thinking he could pay it back on time. He obviously couldn't. Blonde guy forces him into having s** with him in exchange. It's been so long since I picked this up that I don't remember what exactly they did.
Spicy favourites: I can hear it without a microphone, Roses and champagne, Passion
Mild favorites: Eternal contract, Kiss the Abyss
Mild favorites: Eternal contract, Kiss the Abyss