I saw your response to Rose, and honestly, you don't need a boyfriend right now! I had one, and it didn't work out. Most don't at your age, or even mine!
But I guess there's nothing wrong with telling him... But if you do tell him, where do you expect things to go? Again, dating shouldn't be encouraged in middle or high school. Also, do you date with the intent to marry? Do you genuinely picture a future with him? How well do you know yourself and your worldview/ philosophy? Before you even think about a relationship, you should think about those questions, and focus on yourself for a bit!!
And hey, there's nothing wrong with flirty friendships! :p Personally, I think you should just stay friends for right now, and go with the flow. Eventually as you get older, something might happen!! :)
Good luck!!