see his response, if he seems not interested or not flirting back. Then means he is not interested... Otherwise he will be confused and begin to ask u why. Then u get the chance to play with him la...

Don't hide your feeling la, just express him and confuse him la. Say anything but not "Love" or "like", leave the chance for him to say. Can just say "miss him" or feel not happy without seeing him or something...

haha, Enjoy flirting!