He is not the kind of guy that is able to handle being turned down all that well.
There is a part of him that wants to get back at you.
This was the part that blocked you on FB after you blocked him on your end.
However, he was unable to maintain that anger for long because there is a part of him that still wants you and hopes that in some way he still has a chance to get what he whats from you.
He has been staring at you without saying anything because he wants you to notice him and make an attempt to talk to him.
At first, he was using this strategy because he didn’t want to be too obvious that he still wants to engage in sexual activities with you.
However, that strategy wasn’t enticing you to come and talk to him.
That is why he decided to smile at you the last time around.
He was hoping that this would be enough to get you to talk to him again and thereby open up the possibility that he may be able to hook up with you at some point.
You may not have smiled back at him because you didn’t want to give out any signals that you may be interested in him.
It was probably a subconscious reaction.
There is a part of you that may believe that this is a guy that you should just stay away from and not allow back into your life.
However, there may be another side that is still interested in him in some capacity.
Your subconscious mind will often try to protect you in scenarios like this by making you avoid getting caught up in feelings for the other person.
In essence, it encourages you to be more closed off so as to protect yourself from being taken advantage of.