A sitcom elongated to excruciating feature length, “Divorce Invitation” travels through a couple of weirdly unseemly comic episodes before arriving at the third—indicated by the title—which is even more peculiarly unfunny. It’s a misfire on almost all counts.

Actually, the movie is more like three sitcoms uneasily strung together. The first is about the courtship of Michael (Jonathan Bennett) and Dylan Lipnicks (Jamie-Lynn Sigler). He’s a waiter at the restaurant run by her parents Paul (Elliott Gould) and Elaine (Lainie Kazan), who object to the romance because he’s not Jewish—a point emphasized by the fact that his family name is Christian. But he enthusiastically converts, and the wedding goes forward.

The second has to do with Michael crashing a posh country club in order to link up with possible investors for a business deal he and his partners have put together. That leads to his reconnecting with his high school sweetheart Alex (Nadia Bjorlin), a super-rich divorcee with who, it turns out, is as hot for him as he still is for her. Their relationship causes him to stress out over his infidelity, but eventually he asks Dylan for a divorce—only to be informed that she’s pregnant.

Finally the title comes into play when Michael finds out that the pre-nup he signed without reading it requires that to get Dylan’s agreement to de-couple, he has to hold a big ceremony to which he must invite everybody who came to their wedding. So he goes through the process of fulfilling that extraordinary condition. But of course it makes him reconsider his decision.

None of these segments is at all funny. A big part of the problem is that everything is crudely exaggerated, from the heavy-handed Jewish humor of the first episode—which includes an excruciatingly shrill bris ceremony dominated by Paul Sorvino, playing the rabbi as though he were performing in a 30,000-seat stadium and had to impress the people in the back row—to the strained slapstick of Michael’s trying to get into Alex’s estate and the supposedly hilarious cameo by Richard Kind as a lawyer who can’t believe that Michael didn’t read the pre-nup. Of Dylan’s parents, one would expect that it would be Kazan who goes wildly over the top, but she’s actually restrained compared to Gould.

But as troublesome as the supporting cast is, the basic difficulty is with the leads. It isn’t just that Sigler and Bennett have zero chemistry; their approaches are incompatible. She comes across as stiff and wooden (her opening college-lecture scene is awful), while he flails about like someone out of a Three Stooges short. As for Bjorlin, she poses rather than acts, more model than anything else.

Not that anybody could have done much with the thoroughly synthetic script by S.V. Krishna Reddy and his two collaborators, especially since Reddy has directed it in a slapdash fashion that goes along with a physical production on the lower end of the indie circuit.

There may be a place for a picture like “Divorce Invitation” somewhere on cable TV, preferably in an early-morning slot. But asking anybody actually to plunk down money for a ticket is sort of like trying to host a big society dinner at the Lipnicks’ diner. Given the quality, it’s just not the proper venue.