DEAR CAROLINE: My brother-in-law's hideous habit

I really don’t want to go to my brother-in-law’s for lunch. He is arrogant, competitive and quite materialistic – in other words, insufferable. He has always seemed to be my in-laws’ favoured son, which is something he loves to play up to by acting as the genial host and indulging in a little sibling rivalry with my husband. We go to his home on alternate years (my parents in between) and it is always he and his wife putting on a lavish spread in their swanky house for us and my parents-in-law.

Our eldest and their son are the same age, and in the middle of A-level years and university applications. Unfortunately, my brother-in-law seems determined to carry on the competition of his childhood into the next generation. He knows that our son is, in fact, more academic, but whenever he speaks to my husband he always asks how our son is getting on, before talking down his achievements while boasting about those of his own child. Our son is hard-working, but sensitive – and perhaps a little nerdy. He is very anxious about everything this year. I really think it will be torture for him to have his uncle making digs throughout Christmas lunch.

My husband and I have talked about it and would like to back out gracefully, but we are worried about how it would look and whether we’d be letting his parents down.