My wife sister's husband

My wife eldest sister's husband
Born into a middle class family.
Completed university education.
Considered himself a person with high IQ but sadly talk down on every in-law.
Too proud of himself. Mention that all in-laws in his wife side is poor. Also mentioned everyone including his wife has low IQ.

During my younger days he and Irene youngest brother-in-law paid for food whenever the family and in-laws eat out. Irene youngest brother in law has better means. I allow him to pay because he often talk down on us, the real reason was, his pay was much more then mine, I can just cover my family expenses with my pay. Irene pay went to looking after the two children. The was no reason for me to pay because he always begin with money, he was earning a lot. We had been looked down by him from young days to old the older age. Now he on pension payout. We pay our food and reminding him he has low income. But this did not stop him from looking down on us. In order not to upset eldest sister we allow him to continue looking down on us.