How do I deal with the dynamic of letting my son's father be more involved in his life?

So my son's father is basically a non-entity in our lives. He ran away when I was 5 months pregnant and lives in a different country now. He wasn't there when his son was born, and he's only met his son once when he was about 2 months old which ended up being a massive waste of time as he decided drinking and hanging out with his friends was more important than spending time with his son while he was in town.So now my son is 7 months old, and his father has decided he wants to come visit again, and claims that this time it will be different and the sole purpose of his trip is to get to know his son and spend time with him. I have my reservations of course, but if he does end up following through with this, I'm wondering what the best way to go about helping him develop a relationship with his son without being completely overbearing about it.I mean, I've spent the last 7 months losing sleep, changing diapers, making bottles, making my son smile, comforting him when he's crying, going to doctor's appointments, running errands with a grumpy baby attached to me. I'm obviously not perfect nor am I an expert but I'm to the point where I know my son so well. We have a routine that, for the most part, works for us and because I've been doing it on my own this whole time that routine doesn't really incorporate another person into it.So I'm just wondering if anyone has any insight into how I can make sure that my son's routine isn't completely disrupted, but at the same time step back enough to let his dad be involved. I mean, this man has never even changed a diaper before in his life, I have no clue how I'm supposed to feel comfortable leaving him alone with a baby he doesn't even know. I don't want to hover the entire time he's here, but if I'm being completely honest I don't really trust him. I don't want to put him off of trying to be there for his son though.Anyone have any suggestions to make this week that I'm already stressing about not be such a big thing? via /r/Parenting http://ift.tt/2eQfhSY