Is it wrong to be 18 crushing on a 16 year old?

Hello ladies. I have a problem. I am 18 and I have a crush on a 16 year old. He looks older than he really is and he is very mature. We started talkin one night when we first actually met. I'd had him on Facebook for a long time and then one night I was with my friend Nathan and he picked up tayler. We didn't really flirt or nothing that night but then when school started he went to my School. I go to the alternative school. We had a class of just me him and another girl. We all became friends and he messaged me on Facebook. We flirted a lot but sometimes I would say mean things but I was joking. He wants to have sex. But then he is really sweet and doesn't say anything about that. Then he'll post statuss about other girls and how a girl should be treated . He somehow made me fall for him. We talk every day at school and he always makes me smile. I don't know what to so. To me its so weird because I never go younger.... and I want opinions on this.