This guy most likely doesn’t like you.
His mixed signals can easily be misconstrued as mixed feelings.
However, it is likely that he is fully aware of what he is doing and that there are no mixed feelings at all.
He smiles one day and then is mean, calls you names and ignores you the next because he may know that you like him and is looking to take advantage of that.
Every time he smiles, he is giving you a false sense of security just so that he can turn around and become mean to you again.
Even the fact that he recently followed you on social media out of the blue, does not take away from how he has been acting towards you.
This is yet another ploy to make you think that he may like you.
It won’t be long before he chooses to make you feel bad again by being mean, calling you names or ignoring you.
There are some guys who simply prefer this dynamic.
It makes them feel empowered without any of the responsibilities that come with courting a girl.