ok, first off!!!! MENTION IT! if you dont and you have more trouble down tyhe line you will have to tell these parents for the first time "that you have been having concerns from the beginning" they will chalk that up right next to lying. If you dont tell the parents, they have no idea there could be an issue. It can also be chalked up to "mis-communication" always tell the parents! you dont have to go into crazy detail, "your kid is driving me crazy with his screaming" but you do owe it to them and yourself to mention "he seems to have a difficult time some days" that way you can work together with the parent to help resolve the issue. alot of time the issue may stem from something thw parent may or may not be doing at home, if you dont let them know, you may never get to the bottom of it! GOOD LUCK my Dear! this is Not a Fun Situation! usually gets better though. BTW: you do need to find a way to get him used to your dog, that is just like a child not liking your husband or your child, your household comes first and a situation like that can really get in the way of the entire day. Is your dog a in or out dog? do you bring him over to the dog and have him touch him gentle while in your arms, or have him give the dog a treat every day to show how fun and nice doggies can be? these things can become a "deal breaker" if not solved.