DEAR MISS MANNERS: After a phone call with a longtime friend, she neglected to hang up her phone. As I went to end the call, I heard her start ranting about me to someone else in the room. In hindsight, I do regret listening on, but my reaction in the moment was, “I need to hear this.” I am devastated. This was a friend who helped me through a terrible tragedy in my family, and we have known each other for many years. I’ve helped her through some difficult times, too, and just assumed we’d be friends forever. I try not to dominate our chats, and always ask what is going on in her world because…