In a nutshell, adultery is a non-issue in Arizona and, as an act, is totally irrelevant to the division of property, child and spousal support, and custody issues -- except in very, very limited circumstances. The only time adultery comes into play is if the act is committed in front of a couple's child or children. Presuming that has not occurred, the mere act of adultery does not figure when it comes to the conditions of ending a marriage in Arizona.
Rather than the act of adultery, it is the act of expending community-property funds on an extra-marital partner that gets people in trouble. For example, if a wedded partner spends money from a joint checking account on his or her lover's condo or apartment, or buys them jewelry or some other gift, not only could there be a claim for reimbursement, but also a claim for breach of fiduciary duty. Legally, that partner has misappropriated community money, and that is the crux of the issue. In other words, it is a violation of the fiduciary duty of the wedded spouse. There are specific laws in Arizona as to breach of fiduciary duty and its ramifications, and their financial and emotional effect can make dissolution very costly.