Long distance relationship vs. hook up? Help ):?

I'm 16. I met this boy on a cruise a year ago and we instantly hit it off. We stayed up until like 4 every night, he walked me to my room and kissed me goodnight.. He's my dream guy. We talk fairly often and still flirt a lot. But he lives 1000 miles away. He tells me he loves me and how much it kills him not seeing me, and same goes for me about him. He's only a year older than me by the way. But now there's this very persistent boy who really likes me, but Im only really "dating" because every time I kiss him, im imagining it's the guy from the cruise. I know it's wrong leading him on when my heart isnt half as into as his is.. But I don't know what to do. I enjoy hooking up with him but he thinks it's because I like him, when really I'm in love with someone he doesn't even know about.