I used to tell on my xABF to his mom. It never helped. My mom cared because she didn't like seeing me hurt. But she gave up and just basically said I was going to do what I was going to do, and when I left, it'd have to be when I was ready.
Whenever I told his mom that he never stopped drinking (after he told her he hadn't), I'd get backlash. Just tonight I was talking to her about my DS5. I think she feels like with my decision to cut everything off that I will somehow not let her see her only grand kid.
She is paying his rent ($1000.00/month) and making excuses as always. I just don't play into them anymore. She actually said, 'maybe when he grows up, in 2 or 3 years, you guys can get back together,' or something to that effect. I simply said, our lives are forked now but we can all get along for DS5.
My point is don't expect that letting his side of the family know about the problem will help anything. In my experience, they all just resent me for it. His dad, brother, mother, aunts, everyone who knows how he is still thinks some miracle is going to fall from the sky and he's going to 'see the light,' and become or make something of himself.
He gets so wasted he wakes up and pees in places one wouldn't think of. He is paranoid and projects lies he makes up about me in his head onto others. He hasn't paid his own rent in 7 years, has been arrested multiple times. He tried getting a job recently and had 13 pages of records for a background check. He gets fired from jobs. He mooches. He is 35 years old and his FOO still holds onto the flame of hope. The reality is right there staring them in the face, but, they turn their heads and fan the flames onto me.
This is what I have come to know as my own truth: The only person I can change is me. I am in charge of my own destiny. It was just as much my fault for being miserable for so long as it was his for putting that pressure on my life, if not more. I could have walked away any time. Informing his family of his illness may even put more pressure on you and make it harder to leave out of guilt, it did for me.
I found talking to my own mom and my own friends that were separate from him and whom he had no contact with was good for me. I needed to get validation and advice. And even the people who loved me got tired of hearing about something that was so clear to them but so impossible for me to see. My mom said to me, 'if you'd like for someone to mooch on you and hit you over the head with a brick everyday, we can arrange that for you.'