Nasty in law

What do you do when your in law judges the way you discipline your child as first time parents? Not only does he ridicule us as parents in front of the rest of the family but he SHOUTS in his walrus voice to get my son’s attention and then barks in his face to try to discipline him in front of the family. I wanted to stick a boot up his (you know what) but unfortunately we were staying at his house for the holidays. 😖