How high is your relationship with the wolves? It has to be at least 50 / 50. Also, do you monopolize all the time spent while they're there? I mean, are you constantly interacting with them, until they leave? Every second spent playing razzle and feeding treats, rubbing their belly, etc? Because they won't override your Sim's actions to nibble.
It's actually over that. Last time I checked it was 70/50. And, yes, I play with him all the time. I tried greeting him and not spend too much time with him. You know, play with the other dogs and so on, but that also doesn't work. It slightly frustrating really. Should I try moving all the other sims and dogs out? Be the only one on the lot? I have two teens and two adopted white wolves. One was the female pack leader, but she won't bite either.