Schoolmarm alert! If the sight of Santa hitting a candy-cane bong doesn't jingle your bells, by all means skip "A Very Harold & Kumar 3D Christmas." If you're the type who enjoys dancing around a bonfire of mistletoe and yuletide treacle, however, get in line. This film will stuff your stocking with profane, perverse, politically incorrect glee.

In their third outing, Harold Lee (John Cho) and Kumar Patel (Kal Penn) embark on an adventure more daunting than scoring some White Castle munchies or escaping Guantanamo. This time they have to save Christmas after they burn down the 12-foot fir lovingly raised by Harold's father-in-law. The movie is nominally a reunion story reuniting Kumar, who has kept to his slovenly pot-smoking ways, with his old friend, now a buttoned-up family man whose in-laws have made the nativity into a Martha Stewart-style orgy of tradition.

Of course, that reconciliation guff is merely the scaffolding for a slaphappy barrage of holiday heinousness. Every joke is designed to provoke someone's indignation, but context is everything, and the multicultural trash-talk lands equal-opportunity punchlines on every interest group's chin.

The fact that the leads are neither black nor white allows them to take potshots from angles we haven't seen before. The bravura opening sequence manages to insult Occupy Wall Street protesters, fat cat businessmen, Asians, fans of "Platoon," Caucasian dweebs, anyone opposed to poop jokes, and the entire audience who paid extra to watch the movie in 3D.

Harold's sentimental but seething father-in-law is played by the fearsome Danny Trejo in a hall-of-shame Christmas sweater. I couldn't decide if the casting or the costuming was more inspired. There's a fine line separating idiocy and brilliance, and the film by-and- large stays on the clever side of the line.

By now the Harold and Kumar movies have become an ecosystem of inside jokes, throwbacks and running gags. If you're not already up to speed, the appearance of Neal Patrick Harris as a cynical, sleazebag alternate-universe version of himself might not make much sense. Still, his high-kicking turn as the frontman of a crazed musical extravaganza stands on its own. He breaks the fourth wall to anticipate a fourth installment of the series, and I hope it arrives. It's all so wrong that it's irresistibly right.