How Is there any hope?

GUYS AND GIRLS please. I NEED ALL THE OPINIONS FROM BOTH SIDES. Okay, so theres this guy that I know. His name is Colby and goes to my church and teaches with me every Wednesday. We’ve been friends since we were 7. Now that we’re 16 we kinda see eachother differently, if you know what I mean ;). So we talk all the time and he told me about a week ago, that he really likes me. I told him I like him too. We’re NOT dating because I dont go to his school (im homeschooled) and im really concentrating on my 4.0 He’s a really amazingly sweet truthfull, sarcastic at times guy :) the problem? He’s also a HUGE flirt. He flirts and flirts AND flirts more with so many girls. I mean flirting is completely normal but I mean, am I retarted for getting jealous? I talked to him about it because he noticed I was upset and kept badgering me to talk about it. so I said “You flirt so much. It’s unbelievable the amounts you flirt” and he laughed and said “Dork, cmon you know I like you. I flirt, yes, but so does every single guy AND girl in the world. Its no big deal. I like you. okay?” the conversation was over right after that because his ride came. he’s ganna txt me tonight and I don’t know what to say or do. because I get awkward and thats how he know’s im upset about something. I try not to be but he sees right through me. I don’t know what to do. I really really really like him and unlike the ex’s I’ve had, he’s VERY understanding about some things. HELP?