Rita Bennett has been through a lot.
She was married to an abusive husband who developed a drug habit. Paul eventually died in prison, but he did at least father two great kids with Rita, Cody and Astor.
Now, she's seriously dating Dexter, having stayed with him despite his cheating and (made up) heroin problem.
Early in season three, Rita announced that she was pregnant and wants to keep the baby. She and Dexter then got married, and lived happily ever after... until Rita was killed to close season four.
Paul: If they see me here, like this, I'm gonna lose them forever.
Rita: Paul, the one good thing that came out of our marriage are those kids. And I know you love them. But if you want to have any kind of real relationship with them, it has to be with the father they have, not the father they wish they had.
I can't help it, I kill things.Rita Bennett