Hendrix appealed the case to the Kansas Supreme Court. In October 2007, the court ruled 4-2 that Hendrix should have had a written agreement with Harrington.
Hendrix continued his battle by trying to get the U.S. Supreme Court to hear the case. In October 2008, a year after the Kansas Supreme Court ruling, the U.S. Supreme Court decided not to hear the case.
"I'm angry on what they missed out on, the things I've missed out on," Hendrix said of the twins. "The things my family has missed out on."
The words "sperm donor" also angers him.
"I'm more than that," he said. "I despise that term for me."
In 2008, Hendrix began working with Fine Line tattoo artist Jennifer Bohlander on a tattoo design to honor the twins.
"I wasn't ready to do it then," he said.
The twins will turn 8 on May 18, and Hendrix said he felt it was time to add their names so they will always be with him.
"It makes me happy when I look at it," he said.
Hendrix said he knows the twins are living in Lawrence and are doing OK. He hasn't tried to contact them, but he does buy birthday cards for them and is saving each one.
"I want their lives to be as smooth as possible," Hendrix said. "I just want to be a part of it. I know one day they will contact me."