Wilmer Valderrama surprises Demi Lovato at charity concert

Actor Wilmer Valderrama shocked girlfriend Demi Lovato by surprising her at her charity's benefit concert in Los Angeles on Wednesday (18Mar15) night.

The Skyscraper hitmaker hosted and headlined the inaugural event, which raised money for her Lovato Treatment Scholarship Program that helps support mental health treatment.

While Lovato was onstage at Hollywood's Troubadour venue, celebrity blogger Perez Hilton joined her to help moderate a brief question and answer session with fans, and when Hilton pressed Lovato about her relationship with Valderrama, the singer noted that her "heart is broken" that her man couldn't attend the gig, because he was filming in Toronto.

As fans began screaming, Lovato turned to see her longtime boyfriend standing behind her holding a cake celebrating the three-year anniversary of her sobriety, which she celebrated last week (15Mar15).

A stunned Lovato broke into tears and embraced her boyfriend, who then led the audience in singing Happy Birthday to the pop star, and gushed about how proud he is of her achievement.

He told the crowd, "I just got off the plane... There's a million things to say, but what I can say is that it's been a long time since we've seen a role model like her. To see someone who actually has the courage to be who she wants to be. And if you can take anything from tonight, walk away understanding that from today, life will get better."

The two recently professed their love for each other on Instagram.com, as Valderrama noted how "proud and honored" he was of her, while she responded by writing that she "wouldn't be alive today" without the actor's continued support.

The benefit also featured performances from Christina Perri, rapper Sirah, singer Bea Miller, and a DJ set from Lovato's ex-boyfriend Joe Jonas.