But according to the actor's manager Mark Burg, there was a good reason for that: Sheen, 50, was not infected at the time.
"Bree Olson is all over Howard Stern but the truth is she wasn't in Charlie's life when he was HIV-positive and so there was no reason to tell her anything," Burg tells PEOPLE exclusively.
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"His (diagnosis) was long after he fired Bree Olsen from the [Violent Torpedo of Truth] tour."
Unlike Olson, former girlfriend Natalie Kenly, who overlapped with Olson as one of his Goddesses that spring, came to Sheen's defense.
"He is not a monster," Kenly, 29, told PEOPLE exclusively on the eve of Sheen's bombshell interview with the Today show's Matt Lauer.
"He has regard for human beings and cares about people. I do not see him knowingly putting women at risk." (Kenly, who says she is HIV-negative, now lives a quiet life in the Midwest with her young daughter and long-term partner.)
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As for Sheen's well-documented partying ways, Burg reiterates what the actor told Lauer this morning: "Charlie is 100 percent drug-free and has been for months."
To learn more about living with HIV/AIDS today and to contribute in the fight against the diseases, visit amfAR.org.