Singer Demi Lovato is Cosmopolitan magazine's September cover star and, in her interview with the magazine, the star revealed details about her relationship with Wilmer Valderrama.

According to the singer, her boyfriend of five years, Valderrama, is not the jealous type. The actor is friends with Lovato's male pals and even with her ex-boyfriends, including singer Joe Jonas.

"Nick [Jonas] and Wilmer get along great -- Joe and Wilmer too. It's weird. In the beginning, I was like, 'Why the f--- are you friends with Joe?' He was like, 'He's a cool guy.' Yeah, I know. I dated him."

The singer, who posted an image of the magazine cover on Instagram on Aug. 3, also discussed how the only time the couple has ever split was when Lovato, who has dealt with substance abuse in the past, relapsed.

"People say that relapses happen before you use. Your mind starts setting up the relapse before you take that drink or that first hit," she said. "The times we'd broken up, I had already gone to that place of, 'Yeah, this is what's happening.' I didn't realize it at the time, but I just wanted to sabotage everything around me so that I could sabotage myself."

Regardless of their split, Lovato explained that Valderrama remained dedicated to her and helped her get through it, reported People.

"People told him, 'You should probably leave. She's on a spiral, and you're going to be sucked down with it,'" said the 22-year-old. "But he was like, 'I'm not leaving. This is somebody I really care about.'"

The couple has been going strong and are both currently enjoying the success of their work, Valderrama with his television show "From Dusk Till Dawn" and Lovato with the release of her single "Cool for the Summer."

The song is a different sound for the singer, but that is paying off. The track is currently among the top 20 songs in the Billboard Hot 100 charts.