I like a guy and he thinks I don't?
look at him, flirt, just talk to him more, tell him hes hot or something, sounds like your being blunt so just turn it round like a record baby, right round, right round (from awesome song) and be just outright with him and tell him!
tell him, there abs nothing eles you can do, if he thinks you dont prove him wrong. he migth even like you back.
assume he's gay or just not into ya