Is this RC circuit really in series? It looks parallel to me?
Two dipoles are in series when the same current (same electrons!) are flowing through them. 

They are in parallel if they are subjected to the same voltage (they are connected to the same two nodes at their terminals). 

So yes, they are both in series and in parallel. It's not a problem --- it's like to ask if a runner in a party of two is the last one or the second one ;-).