Andy Biersack and Juliet Simms: Fooled Ya! We Got Married 4 Years Ago

Black Veil Brides singer Andy Biersack and Juliet Simms secretly tied the knot ... for the second time.

Talk about a long con -- sources tell us the singers actually got married years ago. We pulled a copy of their marriage license, and sure enough ... it says they did the deed in 2012.

TMZ broke the story ... the couple wed (again) in an undercover ceremony last weekend -- which most people thought was their first go 'round.

We're told their close friends and families were in the know. Last weekend's ceremony was purely to go public for fans.