NTA. I was put in a situation like this (more than once) as the step-daughter. The longest relationship my mom had was when I was 9ish. He tried his best to get me to like him, and I wasnt falling for it (mostly because my mom had so many bfs before him, i assumed he'd be the same and leave us). Also, my father wasn't in the picture anymore. I was jealous. Eventually I grew to like him after they married and had two kids, but, lo and behold, he cheated and left us anyway. He was a great guy, overall, and I wish I'd tried to bond with him more. I regret being so cruel to him, but my defenses were up all the time as an only child of a single teenage, undocumented mom. I don't know the whole story behind wife and her daughter's relationship, but I'd hope that mom at least tried to have real talks alone with her about it. 'Mom will always love her but mom also has wants and desires separate from her because she's a separate person.' You mention that wife is treated like a maid? As a current nanny, I see this all too often. And at 17, it's probably too late for her to change without some intense therapy to remind her the world doesn't revolve around her. I'm glad you told her. I do hope you told her that her behavior is the reason and not her as a person for being alive is the reason...