Schwarzenegger Tuesday issued a statement saying, "I understand and deserve the feelings of anger and disappointment among my friends and family. There are no excuses and I take full responsibility for the hurt I have caused."
Shriver issued a separate statement saying, "This is a painful and heartbreaking time. As a mother, my concern is for the children."
In a building where secrets are tough to keep, Schwarzenegger managed to keep the child he had with a household employee 10 years ago from getting out. Senate President Darrell Steinberg spent a lot time with the governor haggling over the budget and he says he did not know.
But the expensive aides Schwarzenegger surrounded himself with had an inkling some of the infidelity rumors were true, especially after several women the actor worked with on movie sets accused him of groping them in the weeks before being elected in 2003.
A former aide talked to ABC30 of the affair and resulting child, saying, "It's appalling but not at all surprising. None of the political people who were close to Arnold ever believed all his denials about this stuff ... I wish I could say I am surprised. The heartbreaking part is that I'm sure Maria was."
Shriver has since moved out of the family's Brentwood mansion.
In the early campaign days, Shriver was widely credited for helping her husband win office even after the groping allegations surfaced. She continually defended him.
"I've met thousands of when who say they have worked with Arnold and he has been an extraordinary gentleman," Shriver said in October 2003.
Now Shriver joins a long list of political wives publicly embarrassed by cheating husbands.
Some political watchers think this revelation further ostracizes him from his party.
"If you're a Republican, already being questioned by social conservatives as to whether you're a RINO or a real Republican, this kind of scandal only reinforces the point that you're not one of them," ABC30 political analyst Bruce Cain said.
Social conservative groups say this scandal will ruin Schwarzenegger's political legacy.
"This will be what he is remembered for," Capitol Resource Institute spokesperson Karen England said. "I'm glad the woman chose life, but it's unfortunate Arnold would take advantage of someone working for him in this kind of situation, it's just sad."
Schwarzenegger supposedly told Shriver about the child in January as his term as governor was ending.
Michigan's former governor took to Twitter to give her take on his affair. Democrat Jennifer Granholm tweeted, "Another guy guv admits 2 cheating on his wife. Maybe we need more women governors. Guys: keep ur pants zipped, for Pete's sake."
Two of Schwarzenegger's children also used Twitter to share their thoughts. Katherine Schwarzenegger, 21, tweeted, "This is definitely not easy but I appreciate your love and support as i begin to heal and move forward in life.I will always love my family!"
Her 17-year-old brother Patrick tweeted, "some days you feel like shit, some days you want to quit and just be normal for a bit, yet i love my family till death do us apart."
The unidentified mother of Schwarzenegger's secret child, continued working in their home for nearly 10 years after she gave birth, under the same roof as Shriver and the children, telling everyone it was her own husband's child.