Dexter also he then went away from Stella's house, and Jasper's. Actually, Dexter didn't want something like this. And he had gone all the way to Canada to find out where Stella was. But what his dream was just in vain.
Actually he didn't want to do something bad like this to Stella or Jasper either. But he did not think, if it turns out that his son named Immanuel has really done something out of bounds. And also not what he expected. And indeed Immanuel is a child who does not know his own origins.
Dexter is annoyed, because of Immanuel he really doesn't appreciate Dexter's existence as his real father. At first Dexter did not hate his son, because he was not respected as a father. Even if his arrival to Canada ended tragically, and did not live up to Dexter's own expectations.
In fact, Dexter knew that even if Stella did he would also act like this to him. But indeed he never thought that his son would do such recklessness, even though they had just met.