Heartbroken what to do?

ok so i called my mother in laws house today to invite her over to dinner my only sister in law answered the phone and was like being rude to me all i did was mention to my husband what she did i didnt even ***** about it and he was like why do you always need to find some sort of defect on her and anything rude she does he seems to defend her i tell my husband that she hates me but hes like its all in your head all iwant from him is to admit it that she does i dont want him to hate her or to bring it to her attention i just want him to say you know it doesnt matter if she hates you as long as i love you but he always says you know its because she had a tough life and you have to understand but shes only rude to me and gets away with it ive seen her around other people and shes like the nicest person me and my husband had been married for 7 years and im like i cant beleive he starts fights out of something that just came out of a conversation i feel like his sister is first in his life