Tired of my fiancé's family.

My fiancé and I have been together for 3 years. His family has known me for the 3 years. I'm around pretty much all the time, they've all met me. This past weekend was my fiancé's birthday. His grandparents, mom, stepdad, stepbrother, & sister were all in attendance. First of all, they left without us. Then during this dinner, I find out that his grandparents don't know my name, his stepbrother and stepdad made vulgar comments toward me (which my fiancé put them in their place for) and that his mom doesn't agree with our wedding plans and that shes "so goddamn grateful that her son isn't getting baptized as a Christian because he was born Catholic" to which I laughed at because I was RAISED Catholic but converted and so did his sister. Well her parents didn't like that I said my fiancé can do as he pleases and if he chose to be Christian then they need to respect it. Anyway, their are so many things that are off putting about his family. I understand they are his family and he loves them (sometimes) but I'm just sick of being "nobody". From not knowing my name to not knowing how to spell it, to not even acknowledging me. My family cares for him and they've given him comfort, advice, love and even shelter; he has done things that my parents don't agree with but they care for him anyway. I'm so ready to tell them all to fuck off and that they aren't invited to the wedding but I know that isn't the right thing to do. My fiancé says he doesn't even want them there but they have to be there.. I'm simply annoyed.

Catholicism/Christianity is besides the point but I will say that NONE OF HIS FAMILY PRACTICES. THEY ONLY CLAIM CATHOLICISM so that they don't seem like they're not part of anything.