What does it mean when a guy does not talk to a girl but he looks at her?

im in the same situation. i like this guy but when he is around me he acknowleges me like saying two Words but he doesnt talk to me the whole time. but he looks at me the whole time he is there. he can be doing the simplest things like talking to friends and he will be looking at me. but he wont say a Word to me. i personally think that maybe he is ashamed of liking me like he doesnt want his friends to know. because he friends would probably give him crap.