Dean cheated on Tori?

There's trouble in the one ideal marriage Americans turn to for succor in their time of need: Tori Spelling's man, Dean McDermott, has (allegedly) committed adultery.

Us Weekly claims Dean, 47, was in his native Toronto to publicize his show, Chopped Canada, when he decided to spit (figuratively) on his holy contract with Tori so he could have carnal knowledge of one Emily Goodhand, 28, a fan he met that day.

Ms. Goodhand tells Us, "He told me he and Tori had a sexless marriage. I believed him."

No comment yet from Tori or Dean, who have four children together: Liam, 6; Stella, 5; Hattie, 2; and Finn, 16 months.

Tori did issue a holiday snapshot on Wednesday of the four kids in front of a Christmas tree. "As another year comes to a close, I can't help but feel so grateful for all of my blessings," she wrote.

It's JWoww news, stop . . .

. . . the presses! Jennifer "JWoww" Farley, 27,   has revealed via greeting card that she has conspired with fiancé Roger Matthews to bring more of her DNA into the world.

Christmas cards sent out by the couple are signed, "Love, Jenni, Roger and arriving July, 2014 Baby Matthews." JWoww is getting Twitter advice on all things baby from the nation's most beloved mom, Nicole "Snooki" Polizzi, who has a 16-month-old son.

His e-foot in Twitter mouth . . .

Steve Martin did what many have done: He tweeted and lived to regret it.

His is one of Twitter's most dependably funny accounts. But on Friday, when one of his fans asked him to define this word he'd heard, lasonia, Martin did something very unwise. The meaning "depends if you are in an African American neighborhood or an Italian restaurant," he tweeted. (It's a dish, get it?)

Martin has since apologized for the unappetizing comment on his website: "Comedy is treacherous. I used to try out jokes in clubs and the audience's feedback would tell me when I had crossed a line, or how to shape a joke so it is clear. Today, the process is faster. It's your brain, a button, then millions of reactions. But it's my job to know."

- John Timpane

Belieb in his genius . . .

 Is Justin Bieber a true genius - who can hold two opposing ideas in mind and still function, as F. Scott Fitzgerald famously said? "My beloved beliebers I'm officially retiring," he tweeted on the eve of the premiere of his cinematic masterpiece, Believe. An hour later, he tweeted, "The media . . . make up a lot of lies and want me to fail but I'm never leaving you, being a belieber is a lifestyle." On Thursday, he told a Los Angeles radio station he'll hang up the mic for good after his album comes out next week.

A genius? Or just confused?

Tidbits 'n' pieces

Miley Cyrus' music vid "Adore You," which leaked this week, has her "gyrating under a white sheet," says USA Today. There's "lots of licking and rubbing and one night-vision videocamera." . . . Britney Spears is starting her two-year Las Vegas gig on a low note: Her LP Britney Jean sold only 107,000 units in its first week, her lowest debut ever.