Demi & Ashton: Under Pressure

Ashton Kutcher and Demi Moore have always behaved like newlyweds. In recent weeks the famous pair have held hands at a barbecue and football games, danced late into the night in Las Vegas and flirted between takes on-set. Stepping out as a couple, or with Moore’s daughters Rumer, 22, Scout, 19, and Tallulah, 16, in tow, they have long presented a united front. “He knows what he has and the same for her-she appreciates him,” Moore’s close pal Heather Parry told PEOPLE last year. “They have an incredible mutual respect for one another.” But every marriage has its strains. This summer a source says Kutcher, 32, admitted that while he was still happy being married to Moore, 47, he felt restless as the pair neared their fifth anniversary on Sept. 24. “He wanted more out of life,” says a source.

Was Kutcher simply expressing the natural anxiety of a man who wed in his 20s or were there bigger problems in his relationship? The answer may depend on whether you believe the story of Brittney Jones, a 21-year-old California woman who claimed in a tabloid that she had sex with Kutcher after meeting him at a Hollywood bowling alley on July 24. Although the Twitter-addicted couple often respond to rumors online-on Sept. 1 Kutcher blasted a different tabloid account of cheating as “defamation of character”-this time his lawyer responded. “This is not the first, nor will it be the last time the tabloids engage in reckless conduct,” said Kutcher’s attorney Marty Singer.

Those who know Moore say the strong-willed star is well-equipped to weather whatever comes her way-and that she is fiercely protective of her family. “She always looks for the best in a bad situation,” says Parry. “She has a really strong head on her shoulders. Her family comes first.”

Lately “mrskutcher,” as she’s known on Twitter, has also made it clear that she is not afraid to cut loose-with or without her husband. On Sept. 1 she tweeted self-portraits flaunting her age-defying figure in a tiny string bikini-with the photos going viral just as the first round of tabloid rumors broke. That same day in Chicago, where Moore was filming LOL: Laughing Out Loud with Miley Cyrus, she danced to “Thriller” with cast and crew members at Table 52. The next night Moore caught an all-male burlesque performance at Hydrate-with friends and her daughter Scout-before heading to Cuvee nightclub, where she “danced her ass off” until 4 a.m., says an onlooker.

But Moore and Kutcher haven’t stayed far apart for long, and she tweeted photos with her “hubby” (see box) when he visited her on Sept. 18 in Michigan, where she’s filming The Reasonable Bunch. During the visit, a set source says the couple seemed as loving as ever: “She gushes over Ashton. You could hear them laughing in her trailer.” Privately, a source says, the couple are “angry” about the rumors and have instructed loved ones not to inquire: “Kind of a ‘don’t ask, don’t tell’ policy.”

From the moment they first became an item in ’03, Moore and Kutcher have brushed aside talk that their relationship wouldn’t last. When they met, he was an Iowa-bred sitcom actor (That ’70s Show) who had dated actresses Brittany Murphy and January Jones. She had been one of Hollywood’s highest-paid female movie stars and was the mother of three daughters with ex-husband Bruce Willis. Their 15-year age gap made headlines-so much so that when they married in a Kabbalah ceremony (they’re both students of the form of Jewish mysticism) in 2005, skeptics questioned whether it was a prank for Kutcher’s show Punk’d.

Yet friends say the pair were madly in love. “When they started dating, Ashton was insane over her,” says a source who worked on Punk’d when the couple first met. “He only had eyes for her. In the office, he didn’t even joke around with women. He was never flirty.”

But the couple have their differences. Often outrageous in public, Kutcher has become more retiring since his marriage. “He’s changed so much,” says the source. “His personality, the way he dresses-he used to be such a goofball.” Moore is take-charge. “Demi is very controlling. At the beginning of their relationship, Ashton would just follow her around.” Would she tolerate cheating? “If she knew about it, she’d never allow it to continue,” says the source. “If it’s true, neither one of them would admit it. They have too much pride.”

Sources say their desire to have a child together has led to stress. In 2007 Moore told Vanity Fair she “most definitely” wanted children with Kutcher. Although the actor has forged a tight bond with his three stepdaughters, who call him MOD (“my other dad”), a source says “he really wants kids. He’s great with them.”

The pair have long brushed aside talk about the difference in their ages. “At the risk of sounding really cliche, he’s really an old soul,” Moore told Vanity Fair. But others are not so sure it hasn’t finally caught up to the couple. “Somehow I thought it was going to come back to haunt them,” says an industry colleague. “He got married young and, as crass as this sounds, never seemed to have his fill.” Still, “they seemed super committed.” One source of strength is studying Kabbalah, which emphasizes healthy marital relationships.

If Moore or Kutcher is upset by talk of trouble, neither star is letting it show. Sitting in the stands at a high school football game on Sept. 3, “they were very sweet together, cuddling close,” says a fellow fan. “They’re really good together,” adds a source. “I want to believe nothing is happening, because they seem so happy.”