DEAR ABBY: I’ve been in a long-term relationship with my boyfriend, “Mack,” for about 25 years. Eleven years ago we became more like roommates. I asked him to go to couples counseling, but he adamantly refused. He said, “If you don’t like it, find someone else.” Long story short, I began an affair with an acquaintance of ours. After a short time, the affair came to light and Mack agreed to couples counseling, which was very helpful. I cut off all contact with the other man and any social contacts he and his wife were involved with. Mack and I slowly made new friends, and our relationship is st…