I hate to release my inner fuddy-duddy this early in the year. So I’ll blame this rant on having spent the last afternoon of 2007 in a movie theater with a bag of popcorn and a row of tweens.

I went to see “Juno,” the indie comedy about a hip and sarcastic 16-year-old who gets pregnant after what she calls “premeditated sex.” In a rush of wit and grit, she decides not to have an abortion and picks a couple to adopt the baby. The story waddles inevitably to a happy ending and a slew of reviews praising the film for skewering the pieties of both sides of the family-values debate.

I enjoyed this the way you enjoy the bubbly on New Year’s Eve that leaves you with a hangover the next morning. I had the sense of being co-opted into tacit approval of a goofy, romantic story only slightly less plausible than the actual transformation of its author, Diablo Cody, from stripper to screenwriter.

Please allow me a fuddy-duddy disclaimer. I am aware that reel life is not real life. Zoey 101 is not, alas, Jamie Lynn Spears. And “Juno” isn’t meant to be a documentary.

But we are in the midst of an entire wave of movies about unexpectedly pregnant women — from “Knocked Up” to “Waitress” to “Bella” — all deciding to have their babies and all wrapped up in nice, neat bows.

In “Knocked Up,” pregnancy from a one-night drunken stand transforms a slacker babydaddy into a grown-up. In “Waitress,” pregnancy empowers a woman to escape from Husband Wrong to Mr. Right. And in “Bella,” it’s the belly that leads her into the heart of a warm Latino family.

Here is a cinematic world without complication. Or contraception. By some screenwriter consensus, abortion has become the right-to-choose that’s never chosen. In “Knocked Up” it was referred to as “shmashmortion.” In “Juno” the abortion clinic looks like a punk-rock tattoo parlor.

I am supposed to go with the flow and not point a scolding finger at cultural propaganda. But fuddy-duddy be damned. Sitting behind those tweens — girls somewhere between preschool and pubescence — I wondered what was being absorbed through their PG-13 pores.

Need I remind you of the news that teenage pregnancy rates have gone up for the first time since 1991? It’s expected that 750,000 teenage girls will get pregnant this year. With, by the way, some help from boys. We’ve spent about $1 billion on the taxpayer scam known as abstinence-only education. And Jamie Lynn Spears announced her pregnancy, saying, “I was in complete and total shock and so was he.”

Whatever the cost to actual teenage mothers, it isn’t paid by their stars. The only one paying a price for Spears’ pregnancy is OK! magazine, which reportedly put up $1 million for her pronouncement. (I’m OK! You’re OK! Even if you’re 16 and pregnant.)

I don’t want to return to those wonderful yesteryears when Dan Quayle took on Murphy Brown. But we’re navigating some pretty tricky cultural waters here.

On the one hand, liberals who want teens to have access to contraception and abortion don’t want to criticize single mothers. On the other hand, conservatives who want teens to be abstinent until marriage applaud girls who don’t have abortions.

So we have Mike Huckabee saying that Spears made the “right decision” and Wendy Wright of the Concerned Women for America praising movies that show women rejecting abortion. We have liberals who feel like fuddy-duddies darkening the rosy scenario of the motherhood fantasy movies.

There’s an unstated compromise that historian Stephanie Coontz of Evergreen State College sees being acted out by the culture: “Social conservatives are backing off on the condemnation of single mothers. Social liberals are backing off on the idea that it’s possible to have an abortion and not be ruined by it.” This is best expressed by Hollywood, which wants to be all things to all audiences.

Is it still OK to ask whether this cultural “compromise” ends up compromising the future of those kids in my theater?

When Spears told the world she was pregnant, it was described repeatedly, infuriatingly, as a “teachable moment.” It appears that parents are required to create an alternative PowerPoint presentation. Against the endless loop of hip and comic stories, parents are expected to write the crawl — the stuff about relationships, about birth control, about becoming an adult before you become a parent. We’re supposed to write the real life postscript to Hollywood’s happily ever after.

Once again, adults are being called to teach against the cultural tide. Think of it as a casting call for designated fuddy-duddies.