One step at a time, one day at a time. And you are Dad, with Dad responsibilities, not their friend. I’ve seen more than a few kids be brats and end up losers because their Dad wanted to be friends, rather than Dad the teacher, the guide, the rule maker and enforcer, the one to be respected for his knowledge and leadership.
Sounds like you are doing a fine job. Kids tend to hang at the cool Dad’s house. d:o)
I hope you realize just how true those words are. I remember when hubby told our daughter and son they weren't old enough to be his friend but when they were he would let them know. At the time, they didn't understand why but later on they thanked him for it!