Jennifer Lopez stars as Charlotte “Charlie” Cantilini, a professionally aimless young woman who works, alternately, as a dog walker, a caterer, and a medical secretary. One day, she meets a handsome (yet strangely personality-free) doctor named Kevin Fields, played by Michael Vartan. They fall in love and eventually he takes her to meet his mother, Viola (Jane Fonda). Viola is no ordinary mother, though. She’s a legendary talk show host who’s just spent several months in a mental health facility after attacking a Britney Spears-esque pop singer on her show. (This flick gets off on the wrong foot early on, as you can probably tell.)

Viola spends her days chugging back booze and trading quips with her personal assistant Ruby (Wanda Sykes). Seeing her son cheers her up, but when Kevin pops the question to Charlie, all hell breaks loose. Viola doesn’t like the fact that her son is marrying this non-professional girl, so she sets out to sabotage the relationship. When Charlie discovers this plan, she plots revenge, trying to push Viola over the edge of sanity. Regrettably, that’s pretty much all the plot there is.

The humor of this movie has been pitched at the wrong level. The two lead female characters are so sketchily drawn that their feud makes little or no sense. We don’t really understand what these two have against each other, except that they’re both really, really annoying. Therefore, the jokes have no resonance; it’s just 100 minutes of women being cruel to each other (sometimes for real, sometimes in fantasy sequences). Viola slams Charlie’s head repeatedly onto a table and into a cake, tricks her into eating food to which she’s allergic, and tries to sabotage the planning of the wedding. Charlie drugs Viola, beats her over the head with a frying pan, and ruins her expensive clothing. Nothing these characters do in any way resembles the actions of a real human being. Monster-in-Law should have contained more observational humor about the strain that can occur between in-laws. That would undoubtedly have been funnier than the overly broad, slapsticky approach taken here.

The casting is off, too. Jennifer Lopez is wrong for this role. Charlie needs the playful mischievousness of Julia Roberts or the feisty spunk of Renee Zellweger. I’m actually a really big fan of Lopez, which is why it pains me to see her sleepwalking through a lot of her films. In Monster-in-Law, she essentially gives the same performance she gave in The Wedding Planner, Maid in Manhattan, and Shall We Dance? Even though I liked those latter two films, they did not exactly challenged her as an actress. (Ironically, her most interesting performance of recent years was in Gigli.) Anyone who saw Lopez’s work in Out of Sight knows what she’s capable of; it’s time for her to start taking some risks again.

As for Jane Fonda, one can only wonder why she chose this project after a 15-year absence from the silver screen. Quite honestly, the film is an embarrassment to her incredible talents. She’s forced (or, worse, chose) to overplay everything; at times, especially in the early scenes, she resorts to flat-out mugging at the camera. I have no doubt that Fonda could have created an interesting, multi-layered character capable of producing big laughs. Viola isn’t it.

The only things I really liked about Monster-in-Law were the supporting performances. Wanda Sykes is kind of funny playing…Wanda Sykes (she’s always a variation of herself, but hey – it works). Elaine Stritch has an amusing cameo as Viola’s own mother-in-law. Her character’s purpose in the movie is kind of predictable, but the veteran actress at least brings some much-needed life to the proceedings.

There may be some people who like this movie: women who hate their mother-in-law or daughter-in-law. (Personally, I get along really well with my own mother-in-law so I couldn’t relate.) Monster-in-Law ultimately drove me crazy because Charlie and Viola are annoying, unlikable people that I didn’t want to spend much time around. Kevin Fields would be smart to get away from both of them.

( 1/2 out of four)

Monster-in-Law is rated PG-13 for sex references and language. The running time is 1 hour and 41 minutes.