I see why you would feel so hurt. Since you still believe that he thinks, in his mind, that you have no right to tell the kid not to play wii, and, since he is a lawyer and would understand a conversation about rights, I would send him the following message:

- Dearest BF,

I believe that you might still be thinking that I do not have the right to tell the kid not to play wii, so I want to share my thoughts on it.

You are the kid's father and, as such, you have both the right and responsibility to make major decisions concerning the kid, such as the decisions about the kid's education/healthcare, etc. I acknowledge that right and am not trying to take it away from you.

When your kid is in my house, he is my guest, and I, as the hostess, have the right to set ground rules of behavior in my house. I was exercising that right when I limited the use of TV for playing wii.

Your confusion is that you are not seeing the difference between a hostess' right to set ground rules and the parent's right to tell the child what to do. I was not encroaching on your right to direct the course of your kid's life until majority; I was just exercising my right to peace and quiet in my house, and to do that, I had to limit the use of wii.

My general expectation of you as my bf, though, is that you would help me exercise my right to peace and quiet in my house by taking the initiative and communicating the rules of behavior in my house to your kid by yourself, so that I can be spared this duty. The rules of behavior are :

1-
2-
3-

***

The last part is only if you think you might invite them back; otherwise, omit.

I must add... what an idiot . But do not put that in your letter to him.