Help! Partners dog bullies my senior dog

I (31) and bf (35) have 2 dogs between us and my dog is a vulnerable senior dog who is much smaller than my bfs Husky mix (f) dog who is 5yo. His dog barks, growls and nips at my senior (f) dog when I’m at over his house. The behavior used to be just barking but has escalated to nipping. He doesn’t actively address his dogs behavior, there is no discipline or redirection which I think just makes his dog more aggressive. How do I stop his dogs aggression or am I trying to make a relationship work that isn’t working due to his lack of keeping myself and my dog safe? since everyone is asking, I have spoken with my bf about it and he’ll either defend the behavior or will address it but once it gets to be too much, he abandons the training and gives up.