It’s a story as old as Shakespeare: Someone pretends to be someone they’re not; romance ensues.  In Shakespeare’s plays, a disguise was required. Now all you need is Facebook.

Such shenanigans are documented on “Catfish: The TV Show” (MTV, Tues., 10 p.m.). The term comes from the 2010 documentary “Catfish,” in which Nev Schulman, above, tracked down his online lady pal, who turned out to be 40-ish and married. Her husband compared lying internet lovers to catfish that, he claimed, were put in vats of cod shipped to China to stir things up so the cod didn’t get flabby. Thus do “catfish” make life … exciting. Note: His story is fishy ‘cause cod are saltwater fish and catfish are freshwater only.

On the TV series, real people ask empathetic Nev to investigate an internet-only amour. Exploitive? You bet. But the “victim” has assented to televised humiliation. And the stories are rich in drama. Cassie fell into risky behavior after her dad was killed. She “met” a hunk online who coaxed her back to stability. Cassie proposed. Nev discovered the fiance’s true identity: Cassie’s well-meaning girlfriend. Cassie was devastated.

So “Catfish” is definitely much ado about something.