The "Skyscraper" star took to social media app Snapchat on the most romantic day of the year to show off her new sparkler with a photograph of her holding Wilmer's hand.
"So in love..." she captioned the image.
Despite wearing the piece of jewellery on the middle finger of her right hand, some fans became convinced the unusual rock was an engagement ring, and began sending the 23-year-old their congratulations.
However, Lovato moved quickly to silence the claims as she shared the same snap on Instagram.
"I love you so much Wilmer.. Y'all are crazy btw (by the way)... That is my RIGHT hand and my MIDDLE finger I am NOT engaged."
She later declared her love for her man once again by posting an image of the pair as they enjoyed their romantic evening.