Sam Smith and Brandon Flynn caught some rays Thursday in South Florida ... strolling down the street with unmistakable signs they're a couple.
Sam and the "13 Reasons Why" star grabbed some lunch during the trip to Brandon's family home for the holidays.
They've been together for a few months, but seem to be going strong. BTW, Brandon's not as young as he plays on the show -- he's 24 and Sam is 25.
Sam's set to start his tour in March ... so it appears they're getting some last minute quality time in.