Does this guy like me or is he just being a flirt ?

hi i'm 17 and me and this 18 year old flirt alot together ive liked him for 3 yrs and he texts me with hints as to him liking me, like i'll say to him do you lke me and he'll say maybe...Am confused, he always stares at me, and we were out in town one night and these guys were trying it on with me and he protected me and pretended he was my boyfriend so they'de leave me alone. He will also show off around me and fight with his mates, but then for days on end he will sometimes ignore me, i dont no whats going on in his head, weve kissed a couple of times, and whenever he is with me, his hand is always near me somewhere like he will place it on my leg or arm or face, i really like him but dont no whats going on, and now all of a sudden that i've got a boyfriend now he is being dead nice, texting every day and knocking on my door to see me, what shall i do?? deep down i really like him but i'm taken now :(