Retna Ltd. 1 / 7

Heavy sigh. It looks like there could be something to a tabloid report accusing Sandra Bullock's husband, Jesse James, of stepping out on her.

According to People magazine, the couple is "not living under the same roof right now." An insider says the newly minted Oscar winner left their Southern California home on Monday, two days before the latest issue of In Touch hit stands with a cover story blaring, "The Ultimate Betrayal! Sandra's Husband Caught Cheating."

RELATED VIDEO: Scoop: Bullock moves out

Bullock also suddenly canceled a trip to London to attend the premiere and do promotion for "The Blind Side," citing "unforeseen personal reasons." James, meanwhile, deleted his Twitter account.

So far, neither has commented on the allegations, although Jesse was photographed on Thursday wearing his wedding ring.

Just a couple of days before Sandra's apparent exit from the family abode, she and James turned up in Bentonville, Ark., for a company meeting at Wal-Mart's headquarters.

Word is, the much-loved actress talked to the capacity crowd about "The Blind Side," and, with Jesse, led the audience in the Wal-Mart cheer.

It was the latest show of togetherness for the pair, who were side-by-side on the red carpet throughout awards season.

Their seeming rock-solidness at the Oscars (he gushed that she "took his breath away"; she called him "amazing") had many (i.e., us) hoping that the accusations leveled by a "tattoo model" named Michelle "Bombshell" McGee were untrue.

RELATED: See more pics of Sandra

The ink-stained brunette (she has a tat across her forehead reading "Pray for Us Sinners") claims she connected with James after she emailed his West Coast Choppers motorcycle company about possible modeling work and received a personal reply.

The reported mother of two says a face-to-face meeting quickly led to an "intimate and highly charged" affair that was supposedly carried on while Bullock was in Atlanta filming "The Blind Side."

"I would never have hooked up with him if I thought he was a married man," maintains McGee. "He gave me the impression they were separated."

RELATED: The Cheated Hearts Club

Bullock and James met in 2004 when she took her godson on a tour of his "Monster Garage" set. Sparks didn't fly.

"You know, I passed judgment on him," she told Barbara Walters during her pre-Oscar special. "I had the whole list of what someone like him was supposed to be like, and my world is the exact opposite, supposedly, of what someone like, um, Jesse would be. But I was very wrong."

RELATED: Sandra and Jesse and other unexpected couples

After more than a year of dating, they tied the knot in July 2005. It was her first marriage and his third (he has a son and a daughter with first wife Karla James and a daughter with porn star-cum-jailbird Janine Lindemulder, with whom he's been tussling over custody).

Walters asked Bullock why she had waited so long to get hitched.

"You know, I'd always had this feeling that if you got married it was like the end of who you were," she explained. "And I just never met anyone that was bigger than me."

Sandra also admitted that she'd "never allowed myself to be cared for or protected in a relationship." When Babs asked how Jesse protected her, she replied, "Not once asking me to be anything other than what I am."

Read more Hot Gossip