Better watch out – and sit up straight. Sister is back to teach catechism to all you lapsed, relapsed or forgetful Catholics (and the rest of us infidels, too). This time the topic is Christmas, and Sister is here to dispel myths and remind us what we’re supposed to know.

But first, a little discipline is in order.

“What’s with you girls in little skimpy tops?” Sister says reprovingly, handing tissues to the offenders. “A little less Britney Spears, girls, a little more Sister.”

“Spit out your gum,” she orders someone else.

Sister’s Christmas Catechism: The Mystery of the Magi’s Gold plays through Dec. 23 at The Theatre in Old Town. Sister is played alternately by Kathryn Gallagher and Kristin McNeagle. I saw Gallagher.

Those who saw the progenitor, Late Nite Catechism, will be familiar with the shtick. Audience participation is big, much more so in this than in the previous show. Sister asks questions about Christmas, and for that matter about whose birthday is closest to the big day, offering Catholic-related tchotchkes to the winners.

Remember those three kings and the gold, frankincense and myrrh they brought the Baby Jesus? Sister has been wondering for years what happened to that gold. It doesn’t show up anywhere, and Joseph sure didn’t get a room upgrade with it. Sister figures somebody there that night stole it, and she’s going to use her best imitation of “CSI” techniques to find it.

But the pièce de résistance of this show is the manger scene pageant. At the end of the first act, Sister casts the pageant. We had a Mary with a baseball cap, a Joseph whose instructions were “Stand there and look old” and a gent to whom Sister said, “You have a lovely ass face.”

What is it about that parochial school experience that inspires people to voluntarily subject themselves to it again? It’s difficult to say. But the fact is that Gallagher has the proper presence and a terrific way with an ad lib, and her “students” go away laughing. You can’t ask for much more than that.

Sister’s Christmas Catechism: The Mystery of the Magi’s Gold plays through Dec. 27 at The Theatre in Old Town. Shows Sunday through Wednesday at 7:30 p.m. For tickets, call (619) 688-2494 or visit www.theatreinoldtown.com.

If you thought Santa’s sleigh team was a group of nice, quiet, cookie-cutter reindeer, think again. All the toys, shiny paper and tinsel aside, disgruntlement abounds, and now Vixen has filed a sexual harassment charge against the “jolly fat pervert.”

In Jeff Goode’s The Eight: Reindeer Monologues, each member of the team reports in on working conditions at the Pole. And they’re not shy about telling you what they think.

The scene is set pre-show with music that some will consider scurrilous, or at the very least tasteless (sample line: “Hey there, Mr. Muslim, merry fuckin’ Christmas”).

The message: This is not your average holiday fare. Here’s the sleigh team roster: Dasher (Dylan Peden), a Marine-type member of “the elite, the eight” who’s “been makin’ this Christmas run longer than anyone except the fat boy himself;” swishy Cupid (Andre Soriano), the first openly gay reindeer; Comet (Eric Trigg), the reclaimed gang member from Hell’s Herd; Prancer, a.k.a. Hollywood (Alberto Alvarado), more concerned about his next film, Prancer 2, than about Vixen’s charge (“She was no saint,” he says); and aging Donner (Joey George), Rudolph’s dad, a smoker with a bad back.

On the distaff side, there’s Dancer (Caitlin Grady), the Jewish princess who once owned a ballet studio, with a hoot of a riff on zoos; and militant feminist Blitzen, who affirms that “there will be criminal charges” because, after all, “when a doe says no, she means no.” Last but not least is alleged victim Vixen (Kathryn Kelly), resplendent in high-heeled black patent leather lace-up boots and a clingy (and skimpy) red outfit displaying legs that go up to there. Vixen concedes that she did a Playboy spread but notes, “I guess a woman is only a slut if she meets with some success.”

These are not your kid’s reindeer, folks. Much of the humor of The Eight is rude, crude and/or socially unacceptable, but an equal amount of it is also hilarious. If you’re looking for offbeat holiday fare, give this a try.

The Eight: The Reindeer Monologues plays through Dec. 23 at 6th @ Penn Theatre. Shows Monday through Wednesday at 7:30 p.m. and Sunday at 7:00 p.m. For tickets, call (619) 688-9210 or visit www.sixthatpenn.com.

Is there an adult in this country who doesn’t know the story of George Bailey, who gives up his dreams of college and travel in order to help the little people in his home town of Bedford Falls and is then saved from suicidal depression by a rookie angel trying to earn his wings?

I doubt it, but if so (or if you’d just like to be reminded), here’s your chance to fill that lacuna in your education live on stage. It’s a Wonderful Life: A Live Radio Play can be seen through Dec. 24 at Cygnet Theatre, directed by the redoubtable Sean Murray.

On Murray’s visual smorgasbord of a set, the actors assemble for a ’40s radio presentation (made famous by the 1946 film, the story was also performed on the radio). This show is an adaptation of the original radio script, complete with commercials and jingles.

Augmented by Jeanne Reith’s wonderful period costumes, four old-fashioned mics and – the pièce de résistance – a set of amazing items for Foley artist Scott Paulson to create sound effects with, this show is as much fun to watch in production as it is to hear.

Tom Andrew and Amy Biedel (as George and his wife, Mary) head a terrific supporting cast (Melissa Fernandes, David Gallagher, Trevor Hollingsworth, Mark Larson and Veronica Murphy) all playing multiple roles.

It’s a Wonderful Life has become a staple of the Christmas season. If you’d like to get your Wonderful Life fix live this year, Cygnet is the place to be.

It’s a Wonderful Life: A Live Radio Play plays through Dec. 24 at Cygnet Theatre. Shows Tuesday through Saturday at 8:00 p.m. and Sunday at 2:00 and 7:00 p.m. For tickets, call (619) 337-1525 ext. 3 or visit www.cygnettheatre.com.