Because Mr sneaky threatened to have him killed and both Lords know he's an assassin. It'll be in the assassin's favour to get rid of Mr sneaky or make Seungho catch him in the act.
The author is boxed a bit into a corner with the storyline because the husband, Roxy and the maid are so unpleasant but they are also so much in control of everything. Unless there are some clever plot twists, I think we might end up being disappointed. It's definitely great writing and I don't think I've disliked characters so much since The Remarried Empress.
I really appreciate it. It's good to know in advance because it when it happens out of the blue the comments sections always turns into WW3! I'm looking forwards to seeing how the story develops!
I can't wait to read the novel. Thanks for your hard work (づ￣ ³￣)づ
Remember he got his fingers chopped off and his father's place got smashed up. It'll be interesting if he's joined Taesung's enemy.