DEAR ABBY: I have been dating “Mark” for 18 months. Four months ago, his 17-year-old daughter, “Hayley,” started disliking me - my dog, my kids, anything having to do with me. She forbids me from going to Mark’s house when she’s there and has an emotional meltdown every time we see each other. She has major episodes whenever my name is mentioned and has become violent with her sister, “Lily,” Mark and me.