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Demi Lovato took to Twitter on Thursday night to post a touching birthday tribute to Wilmer Valderrama.

In addition to sharing a photo collage, the singer wrote, “To the funniest, most inspiring, incredible man I know.. @WValderrama – thank you for helping me get through my darkest moments.

“You truly are a light to this world and to my life,” she went on. “Happy Birthday!!!”

A humble Valderrama replied a bit later, “who needs presents when the gift of you is real to us all.. Thank you for the blessing of knowing you.”

The actor turned 34 on January 30.

As Gossip Cop reported earlier, while the on-and-off couple remain close, they are not engaged.

Check out a larger version of the photo below!