So theres this boy i like..?

well as the titlte says i just want to know how i could get to know him better, how can i talk to him? He is always with the older lot and when i sit NEAR but NOT by him he always stares at my face.. its really arkward i just see him at the corner of my eye and when i turn to look to him he doesent look away..what do you think he is doing? And he sort of flirts ish....but i dont kn ow what to say. Thing is i don't have that long to get close to him, see he lives in the same town as me but he is moving soon(not that far away) but he is not moving school (thank god)! :) I just want to know what do you think he is doing whilst staring at me and why? And what should i say to him...? I doubt theres something on my face or something but thing is im not the prettiest of all girls and im deffonotly not the slimest of all girls! So i dont know why he was staring my so called ex friend sed that he sed he likes my boobs but... i dont know he just ..well he always looks at my face and if i ask him to stop looking he looks really sad/upset..thing is he doesent do it to anyone else...:/ im soo confused!