Am I being used

im 19 ive been friends iwth a guy for 4 years now and weve always had a very flirty relationship, recently weve become more and more sexual and im confused about what kind of relationship we have.i dont want to just be used as a friends with benefits kind of thing, becuase i know that i have stronger feelings for him than that. its hard to know if he feels more for me than just friends he tells me he loves me but kinda jokingly and im not sure if he rlly means it or possibly he simply says it so that ill do sexual things with him. Im sure theyres no other girls in his life but hes reasonably confident compared to me whos very shy. i can see our friendship becoming more about sex and im not sure how to find out if he has feelings for me beynd just wanting sex and how do i make myself clear that im not up for being a sex buddy and that i have stronger feelings for him. i dont want to lose his friendship becuase he means a lot to me. any advice anyone? x be frank