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The traditional gift for a couple's fifth anniversary is wood, which is probably what Ashton Kutcher and Demi Moore are knocking on as they count down to their milestone celebration on Friday amid rumors that he strayed.

For the third week in a row, Star features the actor on its cover, this time promising, "Ashton's Texts to His Lover: The secret messages to Brittney that will break Demi's heart."

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The Brittney in question is 21-year-old Brittney Jones, who claims that she had a fling with Kutcher after meeting him back in July at the regrettably named Lucky Strike bowling alley in Los Angeles.

She says that even though he was there with Moore, his stepdaughter Rumer and several friends, she still slipped him her number on a cocktail napkin.

"Ashton was really paranoid," Brittney tells the tab of the Twitter-loving star's ostensible fear of leaving an electronic trail. "My phone was broken at the time, so I couldn't receive or make calls, I could only text."

She contends they soon had a "tender," sofa-set interlude at the house Kutcher shares with Moore, a charge that prompted his rep to rail, "Star magazine continuously publishes lies about Ashton Kutcher and many other celebrities. This is not the first, nor will it be the last time they engage in reckless conduct."

In early September, the tab also accused Kutcher of "kissing and groping a hot young blonde" during a rendezvous near an "out of the way bathroom" at see-and-be-seen L.A. restaurant Madeo.

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In response, Kutcher accused the magazine of "defamation of character" and raged that it doesn't "get to stand behind 'freedom of the press' when you are writing fiction."

The couple's tabloid troubles have now landed them on the cover of celebrity-friendly People magazine, which this week features a smiling Moore under the headline, "Demi's Marriage Under Fire: As Ashton, 32, is accused of cheating, the star, 47, tweets her bikini shots and enjoys late nights out. Can their five-year union stand the strain?"

According to the mag, the pair is "angry" over the two-timing talk and has warned their inner circle not to bring up the subject.

"Kind of a 'don't ask, don't tell' policy," says a source.

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Still, they're "presenting a united front," which explains the self-portrait the actress tweeted on Sunday showing her hanging with her hubby on the Michigan set her currently filming flick "The Reasonable Bunch."

"She gushes over Ashton," relays a set insider. "You could hear them laughing in her trailer."

And while Moore does indeed look happy in the shot, Kutcher seems less so, and his frown isn't likely to turn upside down after he sees that an "industry colleague" believes the duo's 15-year age difference is part of the problem.

"Somehow I thought it was going to come back to haunt them," opines the snitch. "He got married young and, as crass as this sounds, never seemed to have his fill."

That said, the spy concludes, "They seemed super committed."

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