To dream that you have been betrayed indicates that you don't fully trust someone or something. You may feel vulnerable and exposed. For instance, if your significant other is out of town and you dream of him or her betraying you, it is a sign that you're not trusting your significant other or any business matter he or she is currently involved in. Otherwise, you may be facing an important decision in dedicating yourself to a project, task, or relationship.
A dream in which you are betraying someone suggests your guilt resulting from actions or thoughts that you are not proud of.