"I think that honesty is always the best bet and that the truth will set you free," said Crow, who caught "bits and pieces" of Armstrong's interview with Oprah Winfrey. "To carry around a weight like that would be devastating in the long run."
Armstrong, 41, and Crow, 50, began dating in 2003 -- the same year that Armstrong divorced his wife of five years, Kristin -- and split in 2006.
Last year, a report from the U.S. Anti-Doping Agency led to Armstrong's downfall. The shamed cyclist was stripped of his seven Tour de France titles and, until now, vehemently maintained his innocence.
During a series of rapid-fire yes or no questions, the retired cyclist confirmed to Oprah last week that he had blood transfusions and used the banned substance erythropoietin (EPO) during his career -- particularly during all seven of his Tour de France victories.