Would it be wrong of me to ask my husband to cut all Communication with his family?

Me and my husband were at his parents and his sister and brother were there. But anyways we have a 10 year old son who is autistic. And well my son had a meltdown there, and his brother sister and mom all called my son a wast of space and that he was retarded. My husband and i both defended our son, and they all got mad and said it was the truth. And if we don't like it to leave. And i was in tears on the way home and i just feel like if his, family thinks that way about our son then whats the use of going over there?