When you're married for years you would think you would know everything about them, including all their family members.
However, one woman was horrified when a present she gave her husband exposed a secret neither of them knew.
The mother, who has a 2-year-old son with her husband, revealed in an emotional letter to Slate's Dear Prudence podcast that she decided to buy her partner a DNA test for his birthday.
However, the results have ended up "poisoning" her marriage as the couple, who were brought up in the same town, found out they are actually related.
"The results came back saying we are actually first cousins on the paternal side," confessed the woman.