Plot-shifting dream

In my dream, a high school friend posted on FB that she was having an ongoing affair with me, and that the sex was good despite being the only thing she'd ever want me for because of our political differences. (The thing is, this HS friend doesn't really exist; in my dream, she was also friends with another HS friend who actually does exist.) My wife saw this post, and was just as angry and hurt as you'd expect. I was apologetic, and at first in my dream I had only been intimate with her once, but at least had the sense not to offer that as a justification. As the dream evolved, I hadn't slept with her at all, and could prove this, but couldn't get my wife to believe the incontrovertible evidence. I awoke from my dream feeling very poorly about myself, as if the accusation had been true.