do you think about him alot? if so you'll dream about him. or maybe he's somewhere in your future.
Because he's on your mind.
if you think about him alot or you feel bad for something that happened between the two of you that might be why.
or if you have feelings for the guy or have remaining feelings depending on the situation any of those could be the answer. think about it.
Dreams are just your subconscious thoughts coming out. Call him.
It really depends on what kind of dreams they are. For example, if they are intimate dreams it could suggest you are interested in him or vica versa. If they're dreams that make you feel afraid of him then you may well have reason to be or if you just feel annoyed at him having woken up then it's might be that he just drives you crazy! ;)
Im gonna answer the way my favorite EP member would say:
There is a dream section on this site and it will offer you insight as to what your dream may mean.