What could be going through his head?

ok so this guy i like recently has started to look at me and not just usual looks he will be walkin in the halls with his head down and gaze up with a friendly soft glance over, sometimes he even gives the look you know, you just know what it means. Well he also started to try to get closer to me on the stairs. He is the type of person that would never be caught at a school game well just after he has flirted with me the day before he showed up at the game with his friend, he has never gone to any games ever before. At the game i arrived late so there were no seats left so i couldn t sit anywhere near him. After this the next week at school he has been completely ignoring me if i look at him or smile he will completely ignore me and when i dont look at him or just glance over him he will look and flash half a smile. What could this mean, and why is he ignoring me?