I have found, in my experience, that the main reason women don't understand men is that they think we are complicated. Women are generally complex, emotional and multi-layered human beings. Men are, in general, simplistic and straightforward. If you want to understand men, stop thinking we are complicated! If he is into you when you are alone its his hormones overriding his inane need of others approval. If he is not man enough to not care what others think then he isn't man enough for you.