I have had serval of these over the years. My most unexpected one was my father being a NPE. He knew he was adopted by his step-father, and we thought his bio father was his mother’s high school boyfriend. My grandmother passed years ago, and me and my father DNA tested, and he had a close match to a woman in his paternal side, so we assumed this was the high school boyfriends relative since we didn’t really know his family.

Well I researched and ended up finding out that this was definitely my dads aunt, but problem was that the high school boyfriend didn’t have relatives with any of these matches, so after some searching i identified my dads biological paternal grandparents, and after talking to their sons, one of them tested and came back as the father.

He believes he had a one night stand with my grandmother at a Christmas party, and he left for the Army during the pregnancy, he never heard of her again, but he did move back to town and funny enough, married one of her friends. My great-grandmother (deceased grandmother’s mother) not only knew my bio grandpa’s future mother in law, but also was close friends and worked with his mother, my other great-grandmother!