Matt, Amber, Carrie, and Jacoba all say they knew they were conceived with donor sperm. What they say they didn’t know, until they had their DNA tested, was that they were related. Along with as many as 70 others, the four half-siblings all share the same donor: their parents’ former fertility doctor, Donald Cline.

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“It’s scary,” says Amber. Carrie says, “It makes me angry. It hurts really bad.”

WATCH: ‘My Mother Completely Trusted Him,’ Says Woman Who Discovered Fertility Doctor Was Sperm Donor

Matt says the day he saw Cline’s picture in a news article, “I immediately knew that I was going to be a part of this because he looked just like me.”

Donald Cline ran a fertility clinic near Indianapolis from 1979 – 2009. Reportedly, many of the children who were conceived with his genetic material still live in the region. Something Jacoba says has complicated everyone’s lives.

“It’s not even us meeting a sibling and the possibility that we may have dated one or married, but it’s also our children. And not even just a cousin. Some of us have older children, so our children could meet an aunt or an uncle. Not just a cousin.”

Watch the video above to learn how else the siblings say learning the truth about their paternity has impacted their lives.

And later, what did Cline say to Jacoba the day she confronted him about violating her mother’s trust?

Check here to find out where you can watch more from Monday’s Dr. Phil.

This program contains sexual content. Viewer discretion advised.

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