“Sleepover” acts as the obnoxious little sister to the much better “Mean Girls,” only without the wit and skillful humor and genuinely appealing performances. The film is probably not evil incarnate, but it’s so irritating you wish it – and just about everyone in it – would just shut up and get out of your room.

This tween-chick flick follows the attempts of four graduating eighth graders, primarily Julie (Alexa Vega of “Spy Kids”), to win a prime lunch spot next year at the high school. To achieve this mighty feat, they must sneak out of the house against the wishes of Julie’s mom (Jane Lynch of “Best in Show” and “A Mighty Wind”) and win a scavenger hunt, beating a group of popular classmates clearly old enough to be pledging a sorority.

But unlike more entertaining tween fare – such as “Freaky Friday” or “What A Girl Wants” – “Sleepover” never comes close to living up to its slight potential. Agewise, most gags are aimed too low for anyone older than 10. A dorky skateboarder who dances funny? A possibly brain-damaged college-age brother who has a pizza-eating race with a dog? Boys pretending to be girls by wearing wigs and singing along to the Spice Girls? What are eighth graders doing with wigs anyway? And why are they listening to music popular when they were 7?

There is also something vaguely unsettling about certain scavenger-hunt tasks. One is to steal the boxer shorts of dreamboat Steve (Sean Faris), which might be just good, harmless fun but for the fact that this romantic lead looks twice as old as Julie; their inevitable hookup is ludicrous, if not illegal. Also icky is the scene in which Julie dresses up, sneaks into a club that apparently encourages the patronage of jailbait, to get her teacher to buy her a drink. The film’s messages, you might say, are mixed.

The prevailing theme, of course, is that popularity is what counts. But there’s no ironic insight to challenge that notion or, at least, put it into perspective.

“Sleepover” seems to realize the mistake, trying to backpedal when, in the nick of time, Julie says that wherever they end up, that’s the best place to be. Not if they’re in a theater watching dreck like this.