In love with a married man

If you aren't going to give me advice on how we can go about this situation please don't comment. I have been having an affair... With one of my close friends husband. I know it's wrong. I know it's shitty. We just kind of fell for each other. He was having marital problems and I was there for him. We are in love and we have decided we want to be together. We just don't know how to go about leaving our families. Him and my friend gave 3 kids together. I don't have biological children with my husband but I have step children that I love like my own. I would still like to be in their lives. Especially since they have no mother figure because she was abusive so I filled that role. We both want to be together and get out of our relationships causing the least amount of damage and hurt possible. I want to continue being friends with her even though I know that won't happen so I want to make this as easy for her as possible. As easy for husband and step kids and as easy as the kids they have together.