Bio Dad, step/adoptive father

So I have an interesting situation here. My biological father left my mom and I pretty much as soon as he found out she was pregnant. A few years later my mom got married and my "dad" wanted to adopt me as his own daughter. My bio dad relinquished his rights as a father, and I didn't learn that I had a different dad until I was 13, and then I didn't meet him until I was 15. My "dad" turned out to be super emotionally and verbally abusive to my mom and sometimes us children, along with being involved in a lot of drugs. My mom divorced him when I was 15. I am unsure if he will be at my wedding because it is hard to know when he will be sober or not, either way, he would try to show up because he loves us even if he's a trash person. My sisters and I still talk to our "dad" and the younger ones have to see him occasionally, but I no longer have to. My bio dad and I have been trying to have a relationship for the last 7 years and it is okay, it's obviously not super strong or anything, but it is nice that he is there. He has been trying to be involved in my life and the lives of my sisters as well. I plan on having my mom walk me down the aisle, as she has always been there for me and she has been a better mother and father than any one man could have been. I would also like to do a mother daughter dance at my wedding, and I am just wondering if it would be rude to do a dance with just her, or if I should do one with both dads or just one? I don't know what I should do and this is very confusing to me. Sorry for the long message, but I figured context would help for any suggestions.