Credit: G Tres/Splash News Online

Is Nick Jonas ready to throw his purity ring to the wind?

The 18-year-old heartthrob and Delta Goodrem, 26, packed on the PDA in Los Cabos, Mexico over Labor Day weekend. The duo were seen affectionately sharing a beach chair, and a shirtless Jonas placed his hand on his Aussie girlfriend's waist. 

Jonas taunted fans on Twitter Monday with the promise of an upcoming major announcement. "I'm getting so excited about sharing my big news with all of you!" he said. "Who thinks they know what it is?"

The star's coyness has led many to speculate that he and Goodrem are engaged. 

In April, Goodrem and her fiance -- former Westlife singer Brian McFadden, 31 -- announced their relationship was over after seven years together. She and Jonas -- who dated Miley Cyrus from June 2006 to December 2007 -- were spotted holding hands together in May. 

Tell Us: What do you think is Nick Jonas' big news?