As unlikely as it might seem, bigamy has provided fairly fertile ground for comedy writers over the years, so “Being Frank” is not exactly an outlier. But in spite of the presence of Jim Gaffigan in the title role, Miranda Bailey’s “Being Frank” is not much of a contribution to the peculiar subgenre.

As Glen Lakin’s screenplay, originally titled “You Can Choose Your Family,” opens (it’s set in 1992, presumably to avoid having to deal with the fact that today’s electronic systems would make leading a double life very difficult), we’re introduced to Gaffigan’s Frank Hansen, who runs a catsup company in upstate New York he inherited from his dad. His wife Laura (Anna Gunn) seems happy enough, though Frank’s very hard on his high-school age son Philip (Logan Miller), whose hope to go to NYU to study music (the kid’s an aspiring songwriter-singer, of course) he nixes, wanting the boy to go to State and follow in his footsteps at the factory. By contrast, Philip’s brainy sister Lib (Emerson Tate Alexander) seems pretty content, being especially close to mom.

Frank is constantly going off on long business trips and is about to embark on one to Japan. Since Laura and Lib are also planning to be away for a few days, frustrated Philip decides to accompany his pal Lewis (Daniel Rashid) on a jaunt to a nearby town, where they can have a good time while staying with Lewis’ uncle Ross (Alex Karpovsky). Ross turns out to be a zonked-out stoner, and more important, Philip stumbles on the fact that Frank’s there too. In fact, he’s having an apparently happy time with a second family: wife Bonnie (Samantha Mathis), athletic son Eddie (Gage Polchlopek) and pretty teen daughter Allison (Danielle Campbell).

Philip worms his way into this brood, pretending to be the son of Richie, a fictional best friend Frank has employed with both his families (just think of Algernon’s Bunbury). His intention, though, is really to blackmail his into financing his NYU tuition costs.

What follows is a broad comedy with some semi-dramatic digressions. The most notable of those is a bonding session between Frank and Philip during a fishing expedition, when the former explains how he was forced into bigamy nearly twenty years earlier—out of good intentions, of course. But most of the running-time is devoted to the equivalent of what might be described as a “slamming door” farce without the doors, in which Laura and Lib arrive in search of Philip and father and son have to collaborate to prevent the two wives from learning the truth. To that intent they recruit Ross, of all people, to clean up his act and impersonate Richie, with unexpected results. There’s a further wrinkle in Philip’s interest in Alison, who is, after all, his half-sister.

Perhaps if the script had been sharpened, the characters made more sympathetic and the direction were less flat-footed, “Being Frank” could have been amusing. As it is, though, it’s a frantic and desperate attempt to extract some laughs from a misguided premise. Gaffigan and Miller literally work themselves into a frenzy to put across the lame material, but to little effect. The supporting cast is pretty much wasted as well, though Karpovsky gets a few chances to show off his deadpan style (and, in an early scene, something else we could easily have done without). Yaron Scharf’s cinematography is at best workmanlike, and Jeffrey M. Werner’s editing is unable add any real verve to a plot that grows increasingly wearying as it rushes on headlong without leaving much of an impression.

Gaffigan is an amiable fellow, but frankly this vehicle doesn’t do him justice.