Faith, I am so sorry you are having to deal with this. Your partner is at fault for not creating boundaries and rules. As long as he encourages this behavior, you are going to lose here. I teach middle schoolers, and, let me tell you, these kids are headed for the Behavior Disorders classroom! Clearly, they are not getting the guidance and parenting they need. I"m also a grandmother to two 4 year old boys, and I have watched with admiration how my daughter and her husband set limits and are consistent with discipline and training. This is not hitting or corporal punishment, but using reasoning and time-out when they test the limits, which they WILL do!
What you have described is very upsetting behavior. Are you willing to let this continue if your partner turns a blind eye?!!! I don't know what to tell you. I think I'd be packing my bags!
Patty