i have been there , done that and doing that. lol .. when a guy acts like that he's not interested in having a relationship. he knows that you are pretty and he wants to flirt and knows that you are willing to flirt back because you like him and believe me knows you like him. he wants to see how far he can go with you .. he is PLAYING the GAME. ...
you have to decide if you want to play or not.. if you do then keep flirting and know that things are not going to change
ignore him and soon he will stop.. make it obvious you don't want to play that game. but you have to choose.