Fiance's Crazy Family...HELP!

Elise
I'm getting married in 8 weeks and My fiance's aunt was throwing me a bridal shower for next weekend but just canceled it and said she's no longer coming to the wedding because her children were not invited to the wedding.  My parents are paying for the entire wedding, and we want to keep it small as my father is sick.  We did not invite 30 of my cousins, so we thought it was fair to not invite his cousins as well.  She called my fiancé yelling at him and calling me a bitch then my fiance's mother got involved and started calling me a bitch as well.  I do not want these people at our wedding, and my family does not want to pay for their food and drinks after how they've treated me and called me names.  
Is it okay to uninvite them even though they are my fiance's family? He says he doesn't want them their either, but I think he might change his mind about his mother. 
The iPhone text messages are from his aunt to me and the other messages are from his mother to him.