Anyone who uses a word like “hate” in the title of a movie must have supreme self-confidence. But self-confidence can be misplaced, and that’s certainly the case with Nia Vardalos, whose attempt to replicate the inexplicable success of “My Big Fat Greek Wedding” falls flat with “I Hate Valentine’s Day,” which she once again wrote, directed and stars in. Simply put, this is a lousy movie, an indie romantic comedy even worse than most of the bigger-budgeted but almost invariably rotten Hollywood examples of that unhappy genre.

It starts with one of the dumbest premises you’re ever likely to encounter. Genevieve (Vardalos), a gregarious flower-shop owner in a fairy-tale Brooklyn where the weather’s warm and sunny year-round (even in February!), stays happy in her personal life by following a simple (and idiotic) rule. She’ll have no more than five dates with any man, believing that any more than that would turn a joyous, commitment-free encounter into a relationship fraught with problematic entanglements. Foolishly, all her stereotypical neighborhood pals not only accept this dictum but turn to her for advice on dating!

The plot kicks in when Genevieve meets Greg (John Corbett, also returning from “Wedding”), the hunky owner of a nearby store that he’s turning into a tapas bar (the sophistication quotient of the script is suggested by its name—“Get On Tapas”). He’s an erstwhile lawyer who’s abandoned the grind for a less complicated life, and before long he and Genevieve are an item. A crisis arrives with their fourth date: Genevieve stays overnight at Greg’s and they spend the next day together. Greg, aware of her rules, takes that extra day as the fifth date and cuts off further contact. She doesn’t and thinks he’s just dumping her. Even after the confusion is resolved, the big question is whether the two, obviously meant for one another, can get together again.

Many moronic script devices have driven Matthew McConaughey pictures, but surely this is flimsier and stupider than any of them. And it’s worked out with a slavish adherence to formula cliché. Need one add that the supporting characters are all stereotypes, too? There are, for example, Genevieve’s two inevitably gay assistants (Stephen Guarino and Amir Arison), whom she’s nicknamed “Oops” and “Uh-Oh” because they repeat those words whenever they make a mistake (which they do with grinding regularity). And the chubby but lovable deli owner down the street (Mike Starr). All three actors are stuck in wretched roles and don’t transcend them, but even they look good beside Gary Wilmes, playing Greg’s self-absorbed, womanizing best friend Cal, who’s certainly one of the most repulsive characters to grace the screen in years, and whom Wilmes exerts no effort to redeem.

But, of course, the main problem lies in the leads. Vardalos, whom some found winning in “Wedding,” is atrocious here. The part she’s written for herself is terrible anyway—the woman is supposed to be lovable (and beautiful) but comes across as a Lucy Ricardo clone without the charm—but she then compounds the error by awful direction, staging virtually every scene with herself at the center, beautifully lit, as she smiles vacuously barely moving a muscle. Of course, the virtue of that customary immobility is demonstrated in sequences where she’s more animated, like a particularly ghastly one in which she pulls up her skirt in the middle of the street and stretches this way and that with it over her head in to straighten her panties. It doesn’t get much worse than that. Corbett, meanwhile, takes laid-back to new levels. It’s almost as if he were trying to disappear into the background, understandably embarrassed by the script—but if so, his laudable ambition was foiled. You can still see him.

There are a couple of bright moments in the movie, mostly provided by Zoe Kazan as a wimpy girl seeking romantic advice and veteran Jay O. Sanders as some sort of deliveryman who shows up periodically at the flower shop to deliver words of wisdom about marriage. But they’re like drops of water in a desert. “I Hate Valentine’s Day” is technically mediocre, but that’s really a step up from the wretchedness of its content. And so we end with the preordained redundancy: I hate “I Hate Valentine’s Day.”