Freshly feted on Inside the Actors Studio, Martin Lawrence has entrenched himself in the mushy middle of the comedy fundament, joining Steve Martin and Eddie Murphy in pumping out inoffensive family comedies that rake in cash. On the heels of Martin’s Cheaper by the Dozen 2, Lawrence unveils Big Momma’s House 2, which turns out to be as warmhearted as the original. The film zooms past the plot contortions needed to get him back in- to the fat suit, plopping Lawrence’s cross-dressing FBI agent down as a nanny for a white-collar family, whose father is selling intelligence to the axis of evil. With a freedom the NSA would envy, Big Momma breaks into his home and work offices while still having time to teach the kids how to shake dat ass. Lawrence is an ingratiating performer, sarcastic and sentimental, and does inventive work with a swivel chair, a bathing suit, and steaming rocks. He’s helped along by Emily Procter, who plays the overworked wife and should be freed from CSI: Miami as soon as possible.