Why does he keep on asking me to meet again and again?

He keeps asking b/c you keep responding to him. What's probably going through his mind is "She's just playing hard to get, so if I keep at it, SCORE!" If you're really not interested, and he's starting to bother you with the persistance, just cut all ties with him completely. No "just friends" meetings, no online chitchat. Then, hopefully, he'll finally get the picture that you have no interest in him, b/c as things stand, he probably sees your meager socialization as encouragement.