Yep, it is a trilogy. It may be oversimplifying things to say it is a about an abusive relationship. There are many mitigating circumstances in the story that explains behavior that appears abusive. I have not read the last one yet, but everything so far between the couple has been consensual. I will warn you that the writing is not that great and the books could really have used a good editor. But somehow the story is compelling in spite of that.