if he has made it clear that he doesnt fancy you then you should accept what he has said-at least he had the honesty to tell you rather than string you along like alot of men do.
he is probably enjoying all the attention you are giving him and you are feeding his ego-he knows you like him wether you have told him or not. He is not a lemon. Have you told him how you really feel about him? chances are that if he doesnt fancy you then i dont think things will go further-and if they do it wont last. You say you dont fancy him yet you say he is growing on you-deep down you like him more than you think. You need to tell him how you feel-as spending so much time with him and the texting is making you fall for him. Maybe dont spend so much time with him-im sure you can still renain good freinds (how did you end up meeting?) and stop texting him so much, concentrate youre efforts on finding someome who does want to go put with you-nd just stay friends with this dude-if youre falling for him too much-back off x