Ariana Grande's new boyfriend got upstaged by her tongue -- which got dangerously close to some powdered donuts ... pissing off the people who busted their asses making 'em.
Ok, first the BF -- Ricky Alvarez, he's one of Ariana's backup dancers, and you can see them engage in some serious mouth-to-mouth PDA in this security cam video ... which wouldn't have come to light if not for the donut incident.
Sources inside Wolfee Donuts in Lake Elsinore, CA tell us the couple came in on Saturday, and decided to play truth or dare with the goods -- daring each other to lick powdered jelly donuts on the counter.
