Hi I think I can help?? The short answer, in my opinion, is that perhaps you were dreaming of a way that would make it feel like less betrayal.
To me it symbolizes what you wish had happened in the first place--not that you wanted her to be unfaithful. That you wanted honesty from her to begin with. Hope this was helpful

Your brain is always trying to work out unresolved problems through dreams. Clearly, part of you is still trying to recover from what she did. Although nightmares aren't fun, they are part of the body's natural healing process. Give it a little time, this will pass.

Anything that causes trauma, whether it is emotional, mental or physical trauma, can manifest itself in dreams in one way or another. Once a person works through the stress that results from the trauma the dreams become much more infrequent or go away completely.

Maybe it's your unconscious mind trying to make peace with the situation.

I think all of these answers are great. You are healing. That's always a good thing :)

for several weeks after separating from my husband, who cheated many times with many women in a very short period of time, i had dreams almost nightly about him.

in the dream, he would appear, and i could already "feel" what was coming, like a sense of dread, and then i would "catch" him cheating or one of his friends in the dream would let it slip, like we'd be standing in a group and they'd misspeak, revealing his infidelity, or a strange woman would appear in the dream and everyone else but me seemed to sense a significance. it was very frustrating. but i think unfortunately, it is somewhat of our subconscious mind trying to wrap itself around such unbelievable betrayal and hurt

This has happened to me before.
I had a real rough break up and I would dream about him a lot .....it is 2 years later and I haven't had one in a while.
I think it is totally normal.