I heard about a theroy that when we dream, we all dream in the same dream world. To test this theory, you have to be conscious that you are dreaming. If you can do that, ask your dream girl what she is doing in your dream.

I heard (or maybe read somewhere don't remeber) of a women asking random people what they were doing in her dream, which one women replied "what are you doing in mine?" I always thought that was the coolest thing.