State laws vary as to whether marital misconduct -- such as adultery -- can influence issues of property division or alimony in a divorce. Some jurisdictions allow judges to consider it, while others don't. Almost universally, however, courts consider whether you spent a lot of marital money on your paramour.
In some states, such as Texas, the court can consider an affair when dividing marital property, but how much this affects distribution often boils down to the discretion of the judge. If he's open-minded, it may not have much of an effect at all. If adultery offends him, he might award your spouse significant extra property. This is in contrast to states such as Illinois, where courts are not permitted to consider adultery or other marital fault, and the statutes specifically provide for this.
Dissipation of Assets
If you spent marital money on your affair, you generally cannot expect an equitable or equal division of property in your divorce if your spouse can prove it. Courts usually adjust for dissipation of marital assets. For example, if all the property you and your spouse own, including cash accounts, has a total value of $300,000, you might normally receive property totaling $150,000, and she would receive the same. If you spent $50,000 on your affair -- expenditures which are unrelated to your marriage or its best interests -- your spouse would still receive $150,000. She should not have to contribute to your dissipation from her share. You would receive $100,000 in property, and the $50,000 you dissipated would be attributed to you.