I have same kind of hallucinations when I am half-sleep during then night. Once I had a sex dream ( while sleeping with my ex ) and I kind of woke up. Not completely, but still. And I saw this another girl I was having sex, even though it was my ex. But the hallucination was so vivid. I thought probably it was still a dream.

The strangest thing was the feeling in my mind, not the sensory input I had. Even though, I *saw* another woman, more frightening was that in my mind.. well, I think I *knew* it was this another woman. After I realized it was my ex, I was kind of freaked out.