Women are generally much better than men at eye coding and reading expressions. It is important to be aware of the girl coding that occurs in social situations. Gay men also tend to eye code more than straight men.
Good friends among guys, however, can learn to develop non-verbal reads of what each other is thinking in a situation via eye coding, which becomes an efficient communication system that does not reveal any secrets to the new people.
You girls are totally eye coding each other right now!