(The following is a personal post from one of our group members.)
Step 1 of the SA program says that I am addicted to lust: "We admitted that we were powerless over lust—that our lives had become unmanageable." Some compulsive forms of sexual acting out were what showed me that I had a problem, but those were actually the result of something deeper, the result of my lust.
I found along the way that that is an important distinction for me. When I focused on trying not to act out sexually, I failed to make any positive gains against my problem. When I instead focused on lust, it became apparent that without lust driving me to act out, acting out didn't happen. But then it also became apparent that the real problem was that I was powerless over lust, unable to fight it or succeed in struggling against it. And that's when Step 1 became a real experience for me. I knew beyond doubt that I was truly powerless over lust--that my life had become unmanageable.
Fortunately Step 2 follows immediately after Step 1, and provided me with some hope that there was a solution outside myself, a powerful God that could and would restore me to sanity. For me, lusting really is insanity, so I needed a God who could do something about that problem. And having learned to surrender my will and life and temptations and lust to Him (Step 3), I am set free from my addiction to lust. And when I am free from lust, any form of sexual acting out just doesn't happen.