Usually people who do that think that you don't know anything and they try to force their ideas on you even though they know nothing. They do it to enforce dominance I think. They try to "be on top". Kind of a primitive way of saying it, but it seems true. You have to show them that you actually do know more (shouldnt be hard because he seems to know nothing). Anything he says about your riding, tell him why you do it and why it works and eventually he will shut his mouth. If something he says is wrong, correct him and tell him why it is wrong. If you want to ride with them again, trying this would probably help. But he doesnt seem to be worth the trouble, so I would just find someone else. You could give the wife a chance by herself, and if that doesnt work out, forget it.
my best friend is my arabian. People always tell me that he's the calmest horse they've ever seen. i tell them he's an arabian. and they are surprised :)