My husband is the same way. Blood is thicker than mud. His daughter has manipulated him to a tea. Now she doesn't even let me be a grandmother to her kids. Well she is going to have a rude awakening because I have decided to draw the line here. She is 16 older than her sisiter and if she wants to treat me with disrespect I can do the same to her. The next time she wants to have our daughter spend the night or go on an outing with her kids, my grandson's the answer is going to be no. She will have to find the answer and hopefully she will get the picture that she can not exclude me from the family. I have been married to her dad for 11 years and have known her for 22 years!
It sure sounds like you've tried with your step children. You know, my father remarried after my mother's death (twice) and I wasn't so happy about it, I am ashamed to say. I never treated the woman badly and was polite, but I was cold. As time went on, I became less so because I moved past what was bothering me (missing my mom, replacing her, etc.) Even though I was an adult, I still was childlike in my response to my dad and his life. I'm over that now, and I only want the best for him and for him to be happy. So what I am trying to say is that his step children sound like even though they are adults, they are emotionally immature. You should consider having a talk with your husband---- they should NOT be rude to you. And he should stand with you on this. You've been nice and accepting to them, they can be immature but not abusive. I'd put an end to that behavior via your husband. And then I would continue to be polite to them. You sound too nice to treat this way forever. Good luck and I hope they see the light!!
Sorry for all the miss spellings.....I never proff anything before sending.
Sorry.