Relationship advice please

Cortney Lyric • Hey, I`m the cutest, thank you.?
Ok, I met this guy in the beginning of the school year and by the second month we were pretty good friends. We're both in highschool he's a junior and Im a sophomore. Im a big flirt so I flirt with him alot because I obviously like him.We talked alot in class we are pretty much non-stop?...And then after we exchange numbers and we get to talking and he tells me about how he really deels about me...and my initial reaction was hes upper class man he doesn't like me he's just playing...but he was persistent and I got the memo that he wasnt joking about it,,,but after that he's becoming more shy...he barely talks to me only when I initiate the convo and when I do he just smiles and blushes....?what does this mean?....?and why is he doing it?.....?and is there anyway I can get around it and put it like it used to be? Thank you...God Bless?