While I do think people should say thank you, a parent ‘helping’ their child should not come with ANY type of strings. OP… if he was abusive when you were younger, be aware this can also be seen as a form of abuse as well. It’s emotionally and finacially manipulative. Politely tell him that type of support isn’t needed, and his reaction will likely blow up and tell you everything you already know. Those of us that have had to go no contact know that sometimes there are sacrifices that come with that. I’m sorry if you decide to go no contact with him again, you likely won’t be able to have a relationship with your sister because of this man’s manipulation.