Demi Lovato engaged too? There for Iggy Azalea engagement

Did Demi Lovato get engaged as well as Iggy Azalea, Ellie Goulding and Colbie Caillat?

Lovato wrote this:

Could not be happier for this woman.. 😆😆😆 (And yes this was literally my face for about an hour) Still can't believe I got to witness that last night.. So happy for you both... Love you so much lady 

Check the ring on Lovato's own finger. Her and Wilmer Valderrama engaged?