I personally believe dreams are a way for your brain's "computer" to sort out all the information that you've acquired throughout the day.
Often, it won't be just the facts and events that your waking brain has witnessed, but also all the bits of information that your subconscious has processed too.
If you have a crush on someone, it's very probable that your mind will be processing information about that special someone.
However, I don't know if this is something you've experiences, but I sometimes have dreams that feature people I haven't even thought about for yours.
Either way, seeing someone in your dreams regularly suggests you've developed a strong mental bond with that person. Whether it's reciprocated would be hard to tell without analysing your crush's dreams too.
Whatever you do, don't ask him whether he 'dreams about you too'. That might seem like you're a little too keen!
