After witnessing a murder, FBI agent Malcolm (Lawrence) takes his 17-year-old rapper-wannabe son Trent (Jackson) undercover with him: Malcolm again becomes Big Momma, while Trent enrols in a girls' performing arts school as Charmaine. While Malcolm plays housemother while seeking evidence needed to lock up the Russian killer (Curran), Trent hangs with the girls, falling for a musician Haley (Lucas). And the school maintenance man (Love) falls for Momma.

The script is mind-numbingly lazy, with obvious plot points and no real sense of comedy. The slapstick is exhausting, as it seems to expect us to find humour in the fact that a guy in a fat suit is, for example, taking a ballet class or playing Twister. This might have been amusing if Whitesell's direction weren't so bland: he misses every joke. And both Whitesell and screenwriter Fogel seem blissfully unaware of the leery sexism that runs through the whole thing.

At least the cast plays it relatively straight. Lawrence keeps his gurning tendencies in check, while Jackson is a likeable lead (even if he looks more like 26, which he is, than 17). The make-up looks great on screen, although we never believe that anyone would fall for it in person, especially one excruciating scene in which Momma poses for a life-drawing class. Clearly, it would take hours for an army of make-up artists to apply these disguises, and yet Malcolm and Trent leap in and out of them in seconds.

The movie does have some guilty pleasure qualities. It's so simplistic that we never need to engage our brains. And the mediocre Glee-inspired songs, including a rip-off of Fame's lunchroom jam, at least have a decent sense of energy. Whether Lawrence will make a fourth movie depends on whether audiences are in the mood for something this shallow. Apparently Nia Long didn't want to return for more, as Malcolm's wife is casually (and clunkily) written out of the story. Note to Jackson: get out while you can.

themes, violence, innuendo

4.Feb.11