<human>: Can you give me the gist of the text in a nutshell?

The relationship has lasted over 10 years so far and it's his first and the only woman he ever had. I'm 21. Let's call her Ann"

I realized that he actually may be in a toxic relationship. He pretty much ended all ties with me my sister and parents 2 years ago. As far as I remember he slowly becomed hostile towards us without a reason. 

Recently I've tried to rebuild ties with him meeting him several times over the course of few months in his place. It seems that every time I visit Ann is so rude towards him, like literally always. Telling him what to do and that he's useless and whatnot. I tried to point this out to her once but she just got furious and he told me to leave...  He runs his own small company which funny enough owns his wife, he works all the time and doesn't have many friends. 

Ann hates his family for god knows why. Especially his mom. I think she convinced him that they (we) don't care about him and stuff which is obviously not true. My parents tried to contact him many times but he always was so rude to them calling them slurs they gave up... 

I called him a few days ago if maybe he would like to go out for a beer, because that's what brothers do, right? But he just told me "If she lets me I'll go" ... And I've never seen him genuinely smile since 2 years.

I kinda think that I'm slowly loosing my brother and therefore would like to ask you: what can I do to stop this madness? Obviously I can't tell him that she is manipulative and toxic because that will only strengthen his belief that we are "the evil ones" trying to lure him away from his family....

e: they have one 3 yo girl, if that helps.

Please help.
<bot>: My brother is in a toxic marriage with older woman [32]. It's his only girlfriend he ever had. How do I help him?