Wilmer Valderrama Has Stood By Demi Lovato Through Thick and Thin

Demi Lovato strikes a pose in a very short and revealing dress on the cover of "Cosmopolitan's" September issue!

In the issue, Demi opened up on her off-and-on 5-year relationship with boyfriend Wilmer Valderrama, and revealed why they broke up a few times.

“The only times we ever broke up were when I was relapsing, whether it was drugs or in a bad place and rebelling against everybody, not just him... People say that relapses happen before you use. Your mind starts setting up the relapse before you take that drink or that first hit. 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.”

[Credit: Tesh/Cosmopolitan]

When Demi went to rehab in 2011, Wilmer did not give up on their relationship. “We started dating when I turned 18… Right after that, I went to rehab. People told him, 'You should probably leave. She's on a spiral, and you're going to be sucked down with it.' 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.”

If rehab weren't hard enough, Wilmer was able to do the impossible — be good friends with Demi's exes, including Joe Jonas! She shared, "It's weird. In the beginning, I was like, 'Why the f--k are you friends with Joe?' He was like, 'He's a cool guy.' Yeah, I know. I dated him.”

Switching gears from her personal life, she shined the light on her music career and compared herself to Rihanna and Nicki Minaj. “There are a lot of girls in pop. 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.”