In the October issue of Shape, LeAnn Rimes explains why she cheated on husband of six years, Dean Sheremet.
"My relationship with Dean was great, but ultimately it wasn't a fulfilling marriage for either of us," says the singer, 28. "We got married so young: I was 19 and he was 21, so as we got older, we grew apart."
Us Weekly first broke the news that she had an on-set fling with actor Eddie Cibrian while shooting a Lifetime movie in late 2008.
Rimes — who now lives with Cibrian, 37, and his two sons, Mason, 7, and Jake, 3 — isn't proud of her behavior.
"I understand why people are disappointed in me, especially since I grew up as America's sweetheart," she says.
She later adds, "I think any relationship is hard to get out of, and I don't think the way I did it was right."
The controversial star says after her fans learned of her affair she got "so depressed."
Recalls Rimes, "I didn't want to get out of bed."
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Looking back, she says, "I truly believe there are lessons in it for me to learn. Cultivating strength from rough situations is the most important thing. After going through this, I know I can face anything."
She also credits exercise with helping her snap out of it.
"Just getting to the gym — even for a few minutes — was a big accomplishment," says Rimes, who appears in a bikini on Shape's cover.
Working out "really did make me feel better and kind of saved me," she adds. "It gave me a bit of sanity. Even now, on days when I'm really frustrated, I'll walk into the gym and say to my trainer, 'We're boxing today. For an hour. I need to hit things.'"
She and Cibrian now go to the same gym.
"Sometimes we take group-cycling classes together, but when it comes to weight training, we pretty much do our own thing," she says. "He's going to kill me for saying this, but when I ask him to work out with me, he always says no. And when I ask why, he says, 'Because your workouts are too hard.' And he's right: I'm serious about my exercise. I don't just doodle around. I see people at the gym talking on their cell phones. If they think their bodies are really going to change … I mean, you've got to put in the effort!"
She says she feels like her body is "changing" and that she is "growing up into a woman. I probably weigh about 6 pounds more than when I shot that cover, but my body fat is the lowest it's ever been. I've gained a lot of muscle, and I feel like I have more curves too."
Her favorite body art? "My butt–well, I've always had a butt–but now I definitely have a butt, which I love."
