So if a married man was in a room with a mute prostitute, they engaged in solo activities (never touching, and obviously never talking), you wouldn't be able to bring yourself to say that's cheating?
The computer screen is irrelevant, talking to the person is irrelevant. Marriage, unlike boyfriend/girlfriend relationships, are a 3-way covenant between the husband, wife, and Heavenly Father. If the sexual desire for someone brings about an action with anything/anyone
other than than spouse, it's quite simply cheating.
You are correct though, in my opinion, if someone had biblical justification for divorce for adultery, I'd like to think we would exhaust all resolutions before giving in to divorce.