It's beginning to look a lot like Chrismukkah

Chrismukkah: a mitzvah to some, a sacrilege to others. Pioneered by Seth Cohen of ''The O.C.," a teen with a Jewish father and a mother he calls ''Waspy McWasp," it's an intermarriage of the two blockbuster December holidays.

In its sunny West Coast way, the hybrid celebration normalizes the country's Jewish-Christian families at a time when many find themselves forgoing both latkes and eggnog to avoid confusion. In the name of domestic harmony and oy to the world, Seth's construction creates a distinctly American (read: theology-free) party, BYO Manischewitz.

But Chrismukkah does make Hanukkah a little less Jewish and Christmas a little less Christian, and for that reason it's not kosher with the more unyielding members of either faith. The movies have had plenty of fun with chopped-liver-versus-pate culture clash, particularly when Barbra Streisand or Woody Allen have been involved. But when Annie Hall tells Allen's Alvy Singer, ''You're what Grammy Hall would call a real Jew," it's funny partly because it's so uncomfortably familiar. Despite our national claims of diversity, partnering outside of one's religion can mean alienating both sets of in-laws and steeling yourself against unintentional and intentional insults. It can mean facing accusations of tainting an entire religious tradition. It can mean dealing with that equal opportunity grinch, guilt.

And so we have a pop cultural salve. After introducing the phrase last season, ''The O.C." has put the promotional push on its holiday this year. The series is airing an amusing Chrismukkah episode tonight at 8 on Channel 25 that revolves around Seth's efforts to find a Chrismukkah miracle, and it is reairing the first Chrismukkah episode next Thursday. And its production company, Warner Bros., is feverishly hawking Chrismukkah paraphernalia such as cards, wrapping paper, and mugs.

There's even a Chrismukkah controversy, as ''O.C." creator Josh Schwartz recently sent a tart message to a company that is capitalizing on his concept by selling its own Chrismukkah products through chrismukkah.com. Addressing the site's Ron Gompertz, Schwartz said, ''In the spirit of Chrismukkah, I will try to make Ron feel guilt -- and at the same time, I will turn the other cheek."

''The O.C." portrays its holiday with the blithe and self-conscious wit that has become its trademark as a nighttime soap opera. Among its many nutty twists, including a hidden love child and an extramarital affair between a divorced couple, tonight's episode showcases a lovingly made ''yamaclaus" -- a red yarmulke fringed with white fur and topped with a white pompom. Played winningly by Adam Brody, Seth is the hour's jester whose post-irony irony (he's a vulnerable cynic) makes the spirit of Chrismukkah irresistible. ''If my sense of the cultural zeitgeist is accurate, and I do believe it is," Seth proclaims tonight, ''this is the year that Chrismukkah sweeps the nation."

The watering down of religions isn't a joke, to be sure. Someday, a TV series could find a lot of rich material looking at the fallout of intermarriage from a dramatic point of view. There aren't many Jewish families in TV drama right now, nor are there many Jews running after perps and pushing gurneys in prime time's genre shows. And that's an issue that may have its roots in the same network skittishness that has led to a scarcity of black and Latino dramas.

But Jewish families have left their mark on TV comedy, where religion is as easy to upend and make light of as sex and love, most obviously on shows such as ''Will & Grace" and ''Seinfeld." ''The O.C." may act like a soap opera, but it's a comedic take on melodrama, and every religious ritual mentioned in tonight's episode is attached to a wink. It reveals Chrismukkah as an emotional joining together of families, no matter how newfangled and spiritually far-flung they may be.

And it can't be a bad thing if families spend a day eating Chinese food and watching Christmas movies, or playing dreidel under the mistletoe. Irreverence should always have a treasured place at every hearth. If Seth Cohen has further secularized the holiday season with Chrismukkah, he has also built a safe house for the interfaith families who already exist and for those who will inevitably follow them. Denying their existence with generic snowflake holiday cards doesn't protect Judaism or Christianity in America so much as it probably distances interfaith families from both of them. Chrismukkah, with its dual citizenship, is a fluffy and sweet little slice of kugel.