Your poor sister sounds like she is incapable of emotional intimacy.
That’s the truth. I felt sorry for her when the “love of her life” ended their 5 year relationship. She was so sure he would eventually ask her to marry him. Later, I found out her idea of the perfect Sunday evening for the two of them was to sit down and tell him every way he had let her down or hurt her feelings during the previous week, thoroughly discuss all the details, and have him tell her how he was going to make it up to her and change so he wouldn’t do it again. I couldn’t believe he’d stayed 5 years...