In the context of her thinking that Hutch might turn Sawyer against her, Vivian saying, "my son" or "our son" would be equally natural to say. I am not saying that Sawyer isn't Hutch's. It could be a slip of Vivian's or it could be nothing. My point was that I did not consider that until I reread the dialogue in Hattyrulz's posted. I am perfectly fine if there is nothing to it. Sometimes authors throw little things like that in the dialogue with a payoff later, and sometimes they are just writing dialogue and choosing one word over another, "my" vs "our." I am OK with either choice by the author.