When Bullock -- America's sweetheart -- married the reformed bad boy and tattooed biker in 2005, they appeared to be an unlikely couple, but as the years passed, their relationship seemed stable and happy.
That changed a few weeks ago after tabloid reports that Bullock's husband reputedly had an affair with Michelle "Bombshell" McGee, a San Diego tattoo and fetish model who reportedly also worked as a stripper.
Though Hollywood often seems like the center of the universe for infidelity allegations, the same drama plays out on a less public scale in homes across the country. But experts say there are ways to sniff out infidelity and, if it's found, how to deal with it most effectively.
According to therapist Bethany Marshall, there can be several clues when one partner may be having an affair.
Pervasive pattern of selfishness. Does he or she only worry about self-gratification?
Excessive secretiveness. Does he or she erase texts from his phone? Screen calls?
Sudden interest in his or her appearance. Is he or she suddenly working out and losing weight?
Renewed interest in sex or trying different sexual practices.
Isabel Gillies, an actress and author of a book on infidelity called "Happens Every Day," said that she had no idea when she was being cheated on.
"People are surprised that you don't know," Gillies said. "But I see a lot of people in these book groups and say 'Does anybody think that their husbands would cheat on them?' and everybody answers 'no.' It's just sad and it's important to look at both sides of the coin and try to see the other person as a whole."
If there is infidelity, Marshall said the next step is to determine what kind of problem the relationship is in.
"There's three types," she said. "There's the one-time colossal mistake with an otherwise good guy. There's a guy who cannot handle the marital stress. And then there's the guy who always wants narcissistic gratification."
Marriages can survive infidelity, Marshall said, but a few things have to happen first.
Offending party has to be sorry. "He [or she] has to be willing to repair the damage by showing remorse," Marshall said.
Admit the affair and why it happened. "If you can't articulate it, how can you fix it?" she said.
The offender must make a plan to fix the problem.
Gillies said repairing the relationship requires both parties, however.
"It's a complex situation," she said. "I think it's important also when somebody does something that's socially unacceptable like an affair. The person who has had the affair happen to them can sort of put a halo on and say, 'You did something really bad.' It's important for both partners to look at how they work together.
"One person can't be a devil and the other can't be an angel," she said.
McGee, the tattoo model with whom James allegedly had the affair, told In Touch Weekly magazine that she began an 11-month relationship with him while Bullock was filming the Oscar-winning "The Blind Side."
When she accepted the Oscar, she publicly thanked her husband. He had tears in his eyes.