I met my DH at a AA meeting. I know he understands the dynamics of addiction inside and out. However, when it came to his older brother he seemed clueless. His brother was a practicing alcoholic and addict who never seemed to be able to get clean and sober no matter what. He called us often, asking if we could pay his rent, which we did. What seemed to be so clear to me, was lost on my DH. For example, his brother at 55 years old did not have a car. My husband thought if he helped him to get a vehicle, it would help him find employment. I saw it 100% differently. In my eyes he brother didn't have a car because he really didn't want the responsibility of car ownership. Why pay for car insurance and gas himself when others were willing to drive him around. I told my husband about what I thought about the subject, and warned him it was a bad idea. Nonetheless he found his brother a car. Not long after his brother got pulled over for drunk driving and as expected, he had no car insurance. The car was impounded and he got arrested. The car sat in the impound lot in the fees added up. We had to pay someone to go get it out since we lived in another state from his brother. I liked his brother but there was no way I wanted him to move in with us and I told my DH this several times. I think intellectually my husband agreed with me that it was a bad idea, but, he still had fantasies about Mike coming to live with us. He loved his big brother very much and thought we could shower him with love and all his demons would melt away. He was a great guy....when he was sober. Sometimes I wished I was the type who could give someone like that a chance, but I just couldn't open our lives to his chaos and dysfunction. DH and I had worked so hard to keep all that kind of stuff out of our lives, and I had my kids to worry about. Not long after the DWI Mike got really sick and a neighbor called 911. His stomach was bloated and he had to have a bunch of fluid removed. My husband talked about flying out to Washington State to be with him. While I didn't tell him he couldn't go, I didnt encourage it either. He called from the hospital a few times and spoke to my husband. He seemed in good spirits and we assumed he'd be out soon. All I could think of was how was this going to effect us, since he most likely would need someone to care for him awhile. That night Mike got out of bed and fell and hit his head. The next day he had three heart attacks and we received a call from DH's niece saying his heart stopped and the doctors were pounding on his chest violently, in a effort to resuscitate him. They broke his ribs even but it was no use, he died. DH was devastated and to this day I feel guilt over not encouraging my husband to go out there and do whatever he had to do to help. I wish I had released my husband to make his own decisions about his brother, short of bringing him to live with us. (I stand by that decision) My hope is that you or anyone else don't have to live with that kind guilt and regret.
Take care and I really hope your SS can be put in a residential program to deal with his heroin addiction.

I'm with tog. There is nothing you can do to save SS. He has to do that himself. You might have some hope of getting DH to see how he is enabling SS. Will he go to meetings? Talk to a counselor about addiction?

All you can do is set your own boundaries and protect your own children.