5. Unpredictable mood swings
When cheating partners run out of excuses, they start making new ones. Sometimes this includes picking fights with you over trivial matters and storming out of the house. This is their way of finding an excuse to get out of the house and go be with the other person. Cheating partners can go from jovial to irritable to enraged in a matter of minutes. When they return they are usually back to normal, with no hint of anger.