Dear Prudence,
My mind is still reeling. My fiancé confessed to me last week that his younger niece is actually his child. He had a short affair with his brother’s wife, who conceived the month her husband was away. They ended things just before finding out she was pregnant, and she lied about the dates to cover it up. My fiancé knew all this and said nothing because he didn’t want to break up their family. My fiancé’s brother is a good guy and I genuinely like him. I’ve never seen a man so devoted to his wife and children. I don’t know if I can spend the rest of my life being a part of this lie. My future in-laws are a close-knit family and everyone frequently gets together. They actually had a family dinner a few days ago which I’ve avoided because I don’t know how I can look at either my fiancé’s brother or his wife in the eye. I also have complex feelings about the “niece”—biologically speaking, she will be my stepchild! I love my fiancé so much but how can I marry into his family knowing what I know now?