My uncle and his wife moved here to be near us They have no family in the town they came from and shortly after that my aunt inlaws brother moved here too. The problem is when we invite my uncle and aunt over for any occasion she brings her brother, he is a nice person. He is very large middle aged man. But has terrible personal hygine smells really bad and wears shirts that are too small and his belly shows and when he sits down his entire bottom shows. Could you give me some advice on the best way to handle this situation?

Don't invite any of them ?
Invite them and tell them he is not welcome and tell them why.

Honesty is a strange thing, you don't have to remember a lie and it opens up talks.