I once met an old boyfriend for lunch.
Over lunch (!) he apologized for our sex life. "Susie" had taught him to be so free and express himself. He was enjoying sex soooo much more now.
You do you. I wouldn't waste my time.
For the sake on not letting him live rent free in your head, you may want to forgive him [not soon, but someday]. You don't have to tell him or anyone else - the forgiveness would be about YOUR head and heart. This is totally separate from any sort of apology. Some people never apologize, some do and don't mean it.