This Is the Way the World Ends - S6-E12
Dexter: I am a father, a son, a serial killer.
Get Gellar - S6-E9
Dexter Morgan: Are you okay?
Debra Morgan: Yeah, I just threw away a pair of shoes because they're full of blood, but I'm great.
Dexter: 'Cause I'm here if you need a chair.
Debra: What?
Dexter: What you said before. I'm a chair.
Debra: Yeah, but I don't want a chair. I want a table.
Dexter: Deb, what are you even saying?
[MC Hammer's "U Can't Touch This" playing.]
Former Classmate: Come on, Dexter. It's hammer time.
Dexter: [internally] I have no idea what hammer time is. Or how it differs from regular time.
Answer: No, Harry is not the real father. While he did have an affair with Dexter's biological mother (Laura Moser), this was when she was his C.I. Dexter was already born at that point.