The porn star was one of Sheen's two "goddesses," the girlfriends he said he loved and who lived in his Los Angeles mansion.
The two women -- Olson and former marijuana model Natalie Kenly -- completed "the three parts of my heart," Sheen has said.
While they portrayed their relationship as close-knit and kinky, it was anything but behind the scenes.
In an interview with ABC News, Olson, 24, acknowledged that things were sometimes tense inside Sheen's home, in part because of Kenly.
"I don't know how to put it. It was like you could cut the air with a knife sometimes," she said. "I felt like I couldn't show Charlie the affection and the love that I wanted to show him, because of how she would react."
ABC News reached out to Kenly for comment but she declined.
Sheen's career imploded this year after bouts of unpredictable behavior, including his trashing of a posh New York hotel while on a bender last fall. In subsequent interviews, the actor claimed to be a "warlock" with "tiger blood" and "Adonis DNA" who took "seven-gram rocks" of drugs while he partied.
Sheen, 45, has been to court numerous times to hammer out a custody agreement with ex-wife Brooke Mueller for the couple's two young sons.
Mueller herself has been to rehab multiple times.
Sheen's life had taken several twists, but on television, things inside his home appeared great.
They weren't, however, especially not between the two women.
"I think she was trying to convince herself that it was great," Olson said of Kenly. "But I mean, she was crying like every day. She was really upset about it."
From Pre-Med to Porn: Always Sexually 'Insatiable'
So how did a farm girl from Fort Wayne, Ind., end up in this public love triangle?
She became interested in the adult movie business when she was a 19-year-old, pre-med student.
"It's something I'd always been interested in. I've always been very insatiable sexually," she said.
Five years later, Olson was a bona fide porn star. That's how she met Sheen. The actor had a long-running interest in adult film stars.
Olson said Sheen made her laugh.
"He doesn't have a regular, 'How's the weather?' conversation, you know?" she said.
The two started dating almost right away. She says she was aware of reports that could be violent -- that he allegedly held a knife to Mueller -- and that he trashed a hotel room with another porn star in it. But she figured it was tabloid misrepresentation.
"I did not get that vibe from him whatsoever," she said of the reports.
Asked if she has ever witnessed Sheen being violent, Olson replied: "No. I've never seen Charlie behave in -- violent in any situation."
She added that she has never felt scared or threatened while she was around him.
She also says she's never seen Sheen do drugs, not even when she moved into his house in February.
But there was one thing that surprised her when she moved in: Kenly, the woman she refers to as "Natty."
Olson said she had no idea that there would be another woman also living in the house.
"On the ride over there, his assistant, Rick, says, 'You know about, did Charlie tell you about Natty?' And I was like, 'Who?' And he was like, 'Oh.' And then I get to the house and there she is, standing in the kitchen. And she did not look too happy to see me there with my bags," Olson recalled.
A week after she moved in, the war between Sheen and Chuck Lorre, the creator of "Two and a Half Men," began.