age difference help

im underage. ive been seeing a older guy. we have slept together so many times. i have only had sex with two people , my first boyfriend who is 17. and the guy who i am seeing now. im 16 and he is 21. i just feel like he knows so much more😍 the way he touches me and every thing just turns me on. his voice his smile EVERY THING. we agreed this would be a casual thing, but i want him. everytime we have sex hes worried about me cumming and not him☺ it's like he makes love to me its not just sex💯 im catching feelings , i dont know what to do ! i want to cut him off before i cant hide my emotions anymore but i can't😩😩