He loves me, but I'm only in it for the sex /:

Honestly, i thought it would be the other way around. He's in college now and I still haven't graduated highschool, but he's waiting for me to turn 16 so it would be legal for us to be together. Looking back, when we hooked up, we both said no strings attatched. We both had just gotten out of a bad break up and had other personal issues and to cope we were basically getting "uti" and having sex. We took a break after he turned 18 because Im still 15 and he's a month or two too old. Anywho, it's been a month and he swears he's in love with me. I didn't believe him because I know how it usually goes with older guys, they want to manipulate you. But he's always trying to be with me, telling me he loves me, he's waiting for me, he talks to his friends about me, etc. So I know that it's genuine, but it's been o n e month and I do recall the both saying there wouldn't be any relationships so I have no idea how to break it to him without breaking his heart and making his life worse than it already is.