The singer uncovered her producer boyfriend's secret life when she moved from Maryland to Los Angeles in 2002, and decided to try to find out more about the unnamed two-timer.
She tells Vibe Vixen magazine, "I found the chick's address; I went riding by. I was calling her cell phone to see if he would be in the background.
"I had her work number, all of that. I heard things about an engagement, wedding invitations... I just wanted the truth."
When she confronted her cheating ex, he admitted he had major problems with monogamy and owned up to his other woman - and Mya agreed to stay with him.
She adds, "I didn't want to be with anyone else. I didn't want anyone else to know my body. So I stayed and dealt."
Mya even tried to ditch her good-girl image to keep her man to herself after he criticised her "diva" like image.
She recalls, "(I said) 'Alright, I'm gonna purchase a gun and start rolling around alone so you can see how real of a bitch I am."
She turned to boxing and shooting to cope with her aggression: "It kept me sane. I became a damn member of the shooting range. It was that serious... I was a mess mentally... (but) the sex was good... That's what kept me there."
Source: WENN