Demi Lovato is ''grateful'' for her boyfriend.

The 'Cool for the Summer' hitmaker has gushed about her 35-year-old lover Wilmer Valderrama, who she has been dating for the past five years, for always being ''extremely supportive'' of ''everything'' she does.

She said: ''We don't share everything with the world. But we do feel comfortable to share a lot. With Wilmer and I and our relationship, he's extremely supportive in everything that I do. He makes me feel confident and beautiful. And I'm just really, really grateful for him.''

The singer - who celebrates her 23rd birthday today (20.08.15) - continued to say as well as Wilmer, she always surrounds herself with ''good people'' who are uplifting and positive.

She explained: ''You just have to surround yourself with people that are going to lift you up spiritually. That's what I do. I surround myself with good people and really rely on others for strength whenever I need it.''

Demi - who is currently working on her fifth studio album - added she thinks her new music reflects her mature outlook, reflecting how both herself and her fans have changed as they've grown up.

She told ''I think my new music is definitely grown up. My music is definitely a lot more confident, sexier, and it's pretty much moving in that direction and embracing who I am as a woman.

''It's about growing together with your fans. Ultimately when you make music it reflects your life and I'm a lot older now so of course it's not going to be about the same thing I was singing about when I was 16 or 17.''