"It strikes me as total b.s.," Clifford Streit said about Bergin's new book, "The Other Man: A Love Story" in Wednesday's New York Daily News.
"Michael and I often discussed Carolyn," Streit said, "And I don't for a minute believe he slept with her after she married John."
Others have found discrepancies in Bergin's tale of his relationship with Bessette, which the former Calvin Klein model said spanned several years, both before and after the Kennedy-Bessette 1996 fairy-tale wedding.
Bergin claims Bessette had two abortions and a miscarriage while she was dating Kennedy and Bergin.
"Carolyn was using birth control as long as I knew her," said a longtime friend.
Writer Laurence Leamer said he spent five years interviewing Kennedy's friends for his own new book, "Sons of Camelot."
"None of those friends think (Bergin's book) is true," Leamer said.