I know what your dreams means!
When we dream that someone has cheated on us it really doesn't mean that they have cheated or will cheat it means that this person has been spending toooo much time doing something else.
What you need to think of is what activity is this person doing or did recently that took time away from you & your relationship.
Alot of woman have the cheating dream when deer hunting season starts.
Hope this helps!
Sage