Miranda Lambert I'm My New Man's Biggest Fan

Country music star Miranda Lambert is singing it loud and proud that she loves her R&B man Anderson East.

Lambert showed up to East's Valentine's Day show at Pearl Street Nightclub near UMass, and hit the stage alongside her man and sang Mariah Carey's "Always Be My Baby."

Best part of this video -- and their whole duet -- Miranda's gripping her beer through the whole thing. 

Miranda and Anderson went public earlier this year, and it's easy to see why he's in to her.

Cheap Valentine's date!