What is happening

My bf tasted my pussy like a month ago since then he is crazy about that. We haven't had sex yet but we've done other stuff. I'm really new to that so I just dont know what is happening. When he does that he fingers me and also licks after he's done that for a while my body starts tingling. I cant feel it and I cant understand whether the feeling is good or not that much. I have no idea if I'm cumming or having a orgasm. After that there is that part of my pussy that hurts. I literally have no idea what and why.