what is going on?!

Well here goes, this might be long but i really really need peoples opinions on this and help me figure out what is going on.

Okay, my best friend has a cousin who i really like, but he has a girlfriend. I started liking him back in the middle of May this year, and i decided to tell him about 5 weeks ago. When i told him, he didnt say weather he liked me or not (reason probably being he has a girlfriend) but he made me promise i wont act weird around him and told me not to feel awkward because he doesnt. Anyway, i think by me telling him how i felt made us closer as we staretd seeing eachother and texting eachother more.

im not gonna go into everything so im just gonna point out the things that are going on that i dont understand.
He texts me every morning with 'Wake up lazy ass. how are you today x'
every time hes around me, he likes to tease me/call me names/laugh at stupid things i say/play fight and he LOVES trying to wind me up just so i retaliate and do exactly the same back to him. he randomly asks me a few times a week to go with him and his friend to the driving range and then go grab something to eat.
Him, his girlfriend and me were all at the same party. he payed most of his attention to me, he sat next to me and bought me drinks. dont get me wrong he paid some attention to his girlfriend but more so me. He knew i felt awkward wearing a dress and every 10 minutes or so he was saying 'why do you feel awkward, you look fine.' and then in the end he said 'do you want an honest opionion? because you look lovely'. then we were in the middle of a conversation and he said 'wow your eyes are really green, they're like proper green. I have green eyes, and green eyes are the best' then smiled. he kept putting his hand on my leg an squeezing it and he dragged me up and held my hand and took me to the dancefloor and put his arm around me and we danced with everyone else.
whenever he is at his cousins (my bestfriend) he always offers to take me home. and everytime im about to get out of the car, he hits me so i hit him back. but the other night i was getting out an he put his hand on my leg and went 'are you alright, i can tell by your eyes your not' and i asked how and he said 'because your noo looking into my eyes when you talk to me' so we both just stared at eachother and i had to turn away because i was so tempted to kiss him and i think he knew that so he just smiled and said goodbye. also, one night he drove me home, he played some songs and then he put on U2- City of blinding lights and skipped right to the part where it said 'you look so beautiful tonight' and turned his head away when i looked at him.

also, we were talking about my liking him the other day and he asked me why im so embarrassed about liking him and i said 'surely you would be too if you liked someone' and he replied with 'No i wouldnt because what can you do about it? but ive told you anyway, its just a phase your going through dont worry about it. but please dont change with me' so i said i wont change as long as you dont and he said 'well i havent changed yet so am not going to now, but it wont last long because all we do is fight and argue. (we fight and argue in a joking around way) but i like the way we fight and argue cause its good fun :) x'

i wanna know what you guys think of all this, im sorry its long and not put together in the best way but i just wrote everything i can remember and threw it all together. i just really need help to understand this guy! thankyou for reading :)