The 20-year-old dated Jonas briefly in 2010. After their May 2010 breakup, he dated Twilight actress Ashley Greene until March 2011, reported Us magazine.
"We were in a relationship and we broke up, and at one point, I was really mad at him. When you go through heartbreaks and things like that, you always have in mind somebody.
It's like when you hear a song on the radio that reminds you of somebody, you're going to be reminded. But keeping that in mind it's a delicate balance," Lovato said. "Now, I can, fortunately, say, that him and his brother Nick, have always been there for me, and are literally family, and like brothers.
We have a great friendship. And we may not be as close as we used to be, but that's OK," she added. Jonas said it was his choice to break off with Lovato in 2010 but he is trying to be a good friend and support system to the 'Heart Attack' singer. Lovato had entered a rehab facility in 2010 to deal with emotional issues.