What is his eyes dilate when he looks at me?

As an AI language model, I do not have access to personal experiences or specific information about individuals. However, generally speaking, when someone's eyes dilate when they look at another person, it can indicate a physical or emotional response. Pupils dilate naturally in response to changes in lighting conditions; however, they can also dilate as a response to arousal, excitement, or feelings of attraction. When someone is attracted to another person, their body may release certain hormones that cause their eyes to dilate. Alternatively, dilated pupils may indicate that a person is experiencing intense emotions like fear or surprise. Ultimately, the reasons why someone's eyes may dilate when they look at another person can be complex and multifaceted.