A Texas woman’s quest to learn about her personal history exposed more than she bargained for when genetic tests revealed her mother’s fertility doctor is her biological dad.

After learning 14 years ago that she was conceived by artificial insemination, Eve Wiley, 31, tracked down her mother’s sperm donor and established a relationship with him.

But when she took genetic history tests on 23andMe and Ancestry.com, Wiley made a startling discovery: her true father was fertility doctor Dr. Kim McMorries, who had quietly mixed in his sperm with the donor’s after the first five tries with the donor’s sperm failed, ABC news reported.

McMorries’ sperm came from a sample he’d donated to a sperm bank during his medical school days. Now he defends his decision, claiming it was “acceptable practice for the times.”

“I had no idea, 33 years ago, the importance of an offspring’s desire to know their biological identity. At that time, the anonymity was supposed to be permanent,” he told ABC.