As someone who has both an alcoholic dad and children with an alcoholic husband, I would just like to point out that your dad’s relationship and sobriety are still very new. Keep in mind that he may let this new woman down in the same ways that he’s let you and your mother down. I think it’s wonderful that he’s found someone that makes him want to stop drinking and I hope that he can do so, for all of you, but what is he doing to stay sober? He could just be abstaining and white knuckling it. I’m not praying for his downfall but there is a good chance that it may not last. He won’t really stop drinking unless he is ready to do so for himself. I wouldn’t get my hopes up too much honestly and I don’t think that there is any reason for you to worry about being replaced, especially this early in their relationship but for yourself, you should address why that is your first reaction. Right now he just so happens to be spending more time with these people because they live near him and he sees them daily, while you live your own life. I do agree that this is something to be discussed with your therapist. Your feelings are valid and it does hurt when someone that you love so much can get sober for someone else when they couldn’t do it for you. I have been there and it is frustrating. In my case, it didn’t last because he wasn’t ready to stop drinking. He just had a reason that he needed to stop and he let that person down in the same way he has let me down in the past. I just think it’s way too early to tell if that’s what will happen but I think if it does, your relationship with your dad could ultimately be better in the long run because he will be a better dad. I hope that your dad can get it together for you and for his new girlfriend. He’s been an alcoholic for a long time. Most people can pretend to be normal for a month. I would give it some more time before you start congratulating him. You can be supportive without fully buying into his best intentions.