You should be friends with everyone BUT HER. You want her to be your lover. If she does not want to be that, then she will just be the mother of your child.
Make her really miss your friendship. If she misses you, she may have a change of heart and start pursuing you.
Decide how you what to split parenting duties. This means when you are with son, wife is doing her thing. Then when wife is with S, you are doing your thing.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712