'JFK Love Child': Now I Don't Want To Know

March 7, 2008— -- The man who told ABC News and numerous other media outlets that he might be the love child of John F. Kennedy now says his quest for the truth has ruined his life and he no longer wants his DNA tested against that of the former president.

Jack Worthington II, who is featured in an exclusive broadcast interview on tonight's "20/20," is standing by his story that his mother told him his father is JFK, but says that if his mother lied, "at a minimum she is emotionally disturbed, if not criminally liable in my view," he wrote in an e-mail to ABC News earlier this week.

Worthington, who is featured in a lengthy article in this week's Vanity Fair magazine, told ABC News that four years ago his mother told him that he is the late president's son.

"I lived my whole life believing in one thing, and then all of a sudden, the blocks have been thrown up into the air," he said.

During the illness, which would eventually lead to the death of the father that raised him, Jack Worthington Sr., Worthington says he wanted to test himself and his children for the genetic disease that his father carried.

"'Mom, we should, everybody should be tested,'" he says he told his mother. "She says, 'Jack, that's not important; you don't have to do that. Your father isn't Jack Worthington. It's John Kennedy,'" Worthington recounts.

Vanity Fair editor David Friend spent almost a year investigating Worthington's claim.

"Well there was this notion that what sort of person would out their own parent unless there was something to back it up?," Friend told ABC News. "And secondly, it seemed sort of the holy grail of journalism." As Friend pointed out, JFK was known for his wandering eye.

In fact, author Laurence Leamer, who has written three books on the Kennedys, said even he was surprised by the number of women that the former president bedded.