Help me find this manhwa

I was reading this manhwa a year ago and I completely forgot the name 😭

Ill just list the stuff I remember:

1. I think the thumbnail is predominantly red.

2. MC is some sort of lawyer or investigator(?)

3. I think the perpetrator is in this situation where he needs to live with the MC

4. There comes a time where the perpetrator blackmails the MC. I actually forgot if its even blackmailing 😅

5. To get more info from the perpetrator, there was this one time that he gave in to the request to have sex/bj with him.

Hope someone can guess it with this information 😅