Brian: You ever hear of the theory that if you kill a butterfly in the past, it can drastically alter the present? Well who knows what else we changed.
(Peter turns the TV on)
Announcer: Tonight on the Tonight Show, movie star George Clooney.
Peter: Oh, he's good.
Announcer: Comedian Dave Chappelle.
Brian: He's funny, like him.
Announcer: And musician Harry Connick Jr.
Peter: Wow, what a show.
Announcer: And now, ladies and gentleman, heeeeeeeeeere's Chevy!
Peter: Oh god Brian, we messed up bad! We messed up real bad!

(to 18 year old Lois) Could I 'Wham' my 'Oingo Boingo' into your 'Velvet Underground'?

Brian

Cleveland: Hey Quagmire, how was your date last night?
Quagmire: Cleveland, it was amazing. You know what I discovered last night? Women have a fourth hole.
Joe: What?
Quagmire: Yeah, I mean it's only visible if you're looking from exactly the right angle, like the entrance to Hogwarts. But ya gotta believe that it's there.
Peter: Man, I envy you single guys. No families, partying whenever you want. These are the only people I get to party with. (holds out his wallet, with a picture of the kids)
Quagmire: (Pointing to Meg) Oh, that's where the fourth hole is, right there. Right there in the back of the knee.

Family Guy Season 5 Episode 18 Quotes

(Lois walks out of Quagmire's house to pick up a letter from the mailbox)
Peter: Lois, what the hell? I'm gone for one night and you sleep with Quagmire?!
Lois: Mr. Griffin, what I do with my husband is none of your business.
Peter: Husband?
Quagmire: Morning, Pete. Hope you and Molly can still join us for dinner tonight. Baby, Let's go play "Schoolgirl & Guy Who Has Sex With Schoolgirl".
(Lois giggles)

Lois: Peter used to be so passionate, but now he doesn't seem to be interested in me.
Quagmire: Lois, if I may, Peter doesn't you. As a friend, I think you deserve to be with someone who knows how to be a gentleman.
Lois: Oh, Glen. You're so sweet. (They embrace) Something's poking me.
Quagmire: It's alright. It's just my wang.