It's good to train your pets.
Claire adopted a new dog who gets stressed around people, and she has some friends who want to come meet the new dog.
Claire wants to let her friends play with her new dog.
Claire tells her friends to come visit next weekend after she has time to take the dog to a class and socialize it a bit.
Claire invites her friends over that afternoon and lets them crowd around and pet the dog.
The dog improves throughout the week and behaves well when her friends come over to visit.
The dog starts to panic and bites one of her friends, and the friend is nervous around the dog from then on.