Same as it is anywhere else in the country.
No, adultery is not a criminal offense in California, so you cannot go to jail for it.
Yes it is.
California is a no-fault state.
Adultery is not illegal - the man will not be prosecuted.
In California, adultery is not a legal ground for divorce, as the state follows a "no-fault" divorce system. This means that you can file for divorce based on irreconcilable differences without needing to prove infidelity. However, if you are separated and your spouse commits adultery, it may have implications for spousal support or the division of property, but it won't affect the divorce itself.
You can't report someone who is committing adultery. If someone is filing for divorce, it may be used as a reason for divorcing and you could inform the person involved in this case.
On the statute books, it may be - but realistically unless it's a really HIGH profile case (considering that it IS California, after all) the reality is close to zero.
No adultery is not illegal in Louisiana. Adultery is not illegal in most states but it is considered immoral.
There is no punishment for adultery in Ontario,
Adultery is not a crime in Minnesota.
Adultery is not illegal in Arizona.
Adultery is not illegal in Colorado.