DNA test results revealed a set of twins were fathered by different men.
The case came to light when a New Jersey woman sought child-support payments from a man she thought was the father of her daughters, who were born in January 2013.
This prompted a paternity test, which revealed that a different man had fathered one of the twins. In her testimony, the woman admitted to having a sexual relationship with another man in the same week.
With the revelation, the Judge ruled the original partner, identified as A.S., should pay child support for only one of the children.
Although this type of case is really rare, it's not the first time it has happened.
The rare phenomenon is known as superfecundation-- it occurs when the ovaries releases two or more ova in one ovulation cycle, and at least two of the ova get fertilized by sperm from separate acts of sexual intercourse. In this case, where two different males fathered the twins, it is known as heteropaternal superfecundation.