It’s got a great premise: statuesque Uma Thurman as a superhero using her powers for revenge on the guy who jilted her.

Many years ago when she was a teenager, Jenny Johnson (Uma Thurman) touched a still-sizzling meteorite which gave her astounding superpowers. Masquerading as a mild-mannered, mousy art gallery curator, Jenny periodically turns into supersonic G-Girl, stopping crime and saving the planet. But when a nerdy architect, Matt Sanders (Luke Wilson), flirts with her on the subway and retrieves her stolen purse, she quickly evolves into his needy, neurotic, extremely possessive girlfriend.

Initially intrigued by her astounding sexual prowess, Matt is soon put off by Jenny’s emotional instability, especially since he’s always had a hankering for a bright, bubbly co-worker (Anna Faris). As the saying goes, “Hell hath no fury like a woman scorned,” particularly when she tosses a live shark in your bed and boils your goldfish. Meanwhile, Jenny’s high school sweetheart (Eddie Izzard) is still in love with her. Yada, yada, yada.

Back in the ‘80s and ‘90s, director/producer Ivan Reitman churned out comedies like “Ghostbusters,” “Stripes,” “Twins” and “Dave,” but he falls flat with this coarse, sexist script by first-time feature-film writer Don Payne, a veteran of “The Simpsons.”

As “Kill Bill” and “Prime” proved, Uma Thurman can be sexy and dynamic, as well as soft and vulnerable – if only she’d been given a better chance. Supporting players like Rainn Wilson (“The Office”) and comedienne Wanda Sykes are wasted.

Finally, I wonder what those MPAA members who gave this a PG-13 were smoking. Filled with crude, raunchy sexual references, it should have been R-rated – parents be warned.

On the Granger Movie Gauge of 1 to 10, “My Super Ex-Girlfriend” is a sour, unfunny 4. It doesn’t fly.