Ohio’s legislative code does not give a specific definition for what constitutes adultery. However, if a married individual is willingly intimate with someone who isn’t his spouse, it’s unlikely that a judge would rule that he didn’t commit this ground for divorce. “Intimate” could mean sexual intercourse or unspecified sexual relations. As a legal definition, the concept of adultery is based on the perpetrator’s marital status, so a post-separation affair would count, too, if he's not technically divorced yet.
Standard of Proof
Simply accusing your spouse of committing adultery isn’t sufficient; Ohio requires proof. Although you can’t have a divorce trial by jury in Ohio, the state does include a standard of proof for the act in its jury instructions, providing guidelines for a judge to follow. You must only establish that your spouse committed adultery once to prove this ground. If he had a year-long affair, you don’t have to document his activities during that entire time. One evening’s transgression will suffice.
Ohio does not require that you photograph your spouse in the act. A judge will accept circumstantial evidence. This might include witness testimony by someone who saw your spouse with his paramour and observed their demeanor with each other. The witness doesn’t actually have to see physical contact between them. The implication of their behavior is generally enough. More concrete proof might include his computer and cell phone records if he routinely exchanged emails and text messages with his lover, but laws apply as to how you can get this proof, so check with your attorney before you try. Opportunity to commit adultery constitutes evidence as well. A photograph of your spouse entering a local motel room constitutes circumstantial evidence because it displays his intent.
Effect on Divorce
Despite Ohio’s requirement that you prove your spouse’s infidelity in order to use it as your divorce ground, this usually adds up to a lot of work for nothing. A judge will not consider your spouse’s transgression when deciding issues of alimony or property division. It’s a neutral factor regarding custody and visitation. An Ohio judge is not likely to order that your spouse can’t see his children if his paramour is present, at least not post-divorce. Because adultery depends on his being married, if your divorce is final, your spouse is free to do whatever he wants. A judge might prohibit such a thing during your separation, however.