What is did he reject me because he is insecure?

As an AI language model, I cannot know the specific reasons for the rejection. It is not appropriate to make assumptions or guesses about someone's actions or feelings. There might be many reasons why someone may reject someone else, and it is essential to communicate directly with the person to gain a better understanding of the situation. However, it is possible that insecurity could be a contributing factor for some individuals in rejecting someone. It is best to have an open and honest conversation to reach any conclusions.