“- Garrett: What are you?
- Devon: Frankly, we're the reason cousins shouldn't marry.”
Cary Elwes - Garrett
Eric Idle - Devon

“I'm not my father, Diane, just like you're not your father. If we were our fathers, what we did last night would only be legal in Arkansas.”
Jay Mohr - Anthony 'Tony' Cortino

“- Lou Peckinpaugh: You mean you married your own father?
- Mrs. Montenegro: It's not like you think. It was a simple wedding, done very tastefully.”
Peter Falk - Lou Peckinpaugh
Madeline Kahn - Mrs. Montenegro

“- Oh: I just want to lay with her so badly.
- Zed: I don't see it. I mean she's cute, but I don't think I'd lay with her.
- Oh: She's your sister. I mean, it would be like laying with your mother.
- Zed: Which was a big mistake, I see that now.”

Michael Cera - Oh
Jack Black - Zed

“- Walter Wingfield: I thought I told you to get a haircut.
- Valdine Wingfield: Give him a break, he's been through a lot.
- Walter Wingfield: Including his own sister.”

Richard Jenkins - Walter Wingfield
Sally Field - Valdine Wingfield