airport lax Demi Lovato pink hair engagement ring

Anytime a rock is on that finger, we have to wonder!

Demi Lovato made her way through LAX last night, and the diamond sparkler on her left ring finger was hard to miss!

Although her rep has denied she's set to tie the knot, rumors of an engagement to boyfriend Wilmer Valderamma started swirling after the "Skyscraper" singer tweeted a picture of herself wearing it with the caption, "Sooooo I don't think I've ever been happier in my life than this very moment that I am fully living in..."

The former X-Factor judge didn't help calm the whispers, either, when she posted a message gushing about her actor beau, who turned 34-years-old yesterday.

"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.. Happy Birthday!!!"

She could just want to keep the happy news private for a while?