The TLC singer and the musician dated from 2001-2004.
In the latest issue of People, the "No Scrubs" singer is sharing why things didn't work with the "Burn" singer.
"We definitely had some chemistry," the 52-year-old songstress told People. "But working chemistry does not mean it works in your personal life. If we were working, it was great. But outside of that, we're so different."
She continued, "It looked great, but in real life ... he knew he had to be a certain way with me and he couldn't."
Chilli, whose real name is Rozanda Thomas, and Usher dated from 2001-2004. Over the course of their relationship, she appeared alongside the singer in his music videos and on red carpets. However, the "Creep" singer revealed that their relationship ended due to different values and trust issues.
Chilli revealed that she cut off contact for good with the "Confessions" singer in 2019.
"I even stopped dating. Because before that I thought if I met the right guy during that time that I wasn't over [Usher] it wouldn't work. I would never want to straddle the fence," she told the magazine.
Today, Chilli is happy and in love with her boyfriend Matthew Lawrence. Chilli and Lawrence confirmed their relationship in January. At the time, her rep told ET at the time that the two had been dating for a few months and were meeting each other's families.
As for Usher, he is currently in a relationship with record executive, Jennifer Goicoechea, with whom he shares two children.
Last month, during a game of Spilling the E-Tea with her longtime friend and TLC bandmate, Tionne "T-Boz" Watkins, Chilli dished on the start of their romance.
Having seen him in "a few movies," she admitted she "always thought he was so cute. Like always."
"And then when I saw him in person, I was like, 'Oh, OK.' And you know how I am," she continued. "So, long story short, once we started talking on the phone and getting to know each other, [we] obviously [have] so much in common. And it was just a lot of things that we would talk about... And he is a phenomenal man. I just saw it right away, and I was just like, 'Wow.'"