That was a big secret for everyone to keep all those years. My ex had a cousin who was an only child. My mom knew my mother-in-law in high school and said she thought she was pregnant at one point back then. That was before she was married and had her family including my ex. Turned out with DNA testing that the cousin, John, was really my exes brother raised by my mother in laws aunt and uncle. We always thought John's parents were pretty old. My mother-in-law adored John. No wonder.

The aunt and uncle were great parents and he loved them and was never told who his mother was until all of them had died.