Demi Lovato admitted that she was once envious of Miley Cyrus.

"There was a time when I was jealous of people who were able to party," Lovato revealed in her cover story for Cosmopolitan's September issue, as quoted by E! News. "For instance, Miley, in her music video 'Can't Stop,' her whole thing was partying and not giving a f--k. Part of me was super jealous that I couldn't be like that. I had to look at my life and be like, 'OK, that's just not what you can do. There's no need to be bitter about it.'"

The "Cool for the Summer" singer also talked about the pop music scene and her relationship with boyfriend Wilmer Valderrama. According to the former Disney star, the only times she and Valderrama broke up was when she was relapsing.

"People say that relapses happen before you use. Your mind starts setting up the relapse before you take that drink or that first hit . . . I didn't realize it at the time, but I just wanted to sabotage everything around me so that I could sabotage myself," Lovato told Cosmopolitan.

The former Disney star began dating Valderrama when she was 18, right before her rehabilitation. She recounted how at the time, people advised Valderrama to get out of the relationship because Lovato was "on a spiral," and he's going to be "sucked down with it," the magazine added.

"But he was like, 'I'm not leaving. This is somebody I really care about.' We relate on a lot of levels. I've seen a lot of s**t. S**t people don't know about. He's seen a lot of stuff too," Lovato explained to Cosmopolitan.

The 22-year-old recording artist also revealed that Valderrama isn't the jealous type, and is even friends with Lovato's "Camp Rock" co-star and ex-boyfriend Joe Jonas, the magazine noted.

Lovato, who is gearing up to release her fifth studio album, revealed that her upcoming music will feature her badass part, which will put her beside Rihanna and Nicki Minaj in the pop industry.

"There are a lot of girls in pop," she said in her interview with Cosmopolitan, as quoted by Entertainment Weekly. "They have badass lyrics, but I feel like I'm the only person other than Rihanna and Nicki Minaj who isn't afraid to say, 'Try something on me and I'll f-king beat your ass.' There are people who can dress up and play the part, but their music doesn't say it."

Last February, Lovato revealed that her new album will be her "best work yet" and will showcase "game changing music," such as rock/pop, "provocative songs," and "a lot of rhythmic flares," MTV added.