A best man (Wilson) stays on as a houseguest with the newlyweds, much to the couple's annoyance.

Dupree: [riding off on his bike] I'll be fine.
[almost immediately is knocked off by a car]
Dupree: The doctor said most of my injuries are emotional.
Molly Peterson: When did we get HBO?
Dupree: Yeah, you saw that. I upgraded us, and I'm going to go halfsies on it 'cause I love it also.
Carl Peterson: What's with this 'Roman Holiday' obssesion? Your favorite movie is 'Fletch'.
Dupree: It's in my top five, but it's not my favorite.
Carl Peterson: Dupree, what you did in our bathroom last night was disgusting. Molly nearly passed out.
Dupree: I know, I know. Believe me. I'm never eating Buffalo wings again. I don't care how much I love them. I'm off them.
Dupree: [after fallling on the skateboard] I've wracked my little Duprees!
Carl Peterson: You get your first ten-speed bike, and suddenly you're Lance Armstrong.
Dupree: Let's leave Lance out of this. Guy's done more with one testicle than you and I could do with three.
Molly Peterson: So you really were serious about Audrey Hepburn, huh?
Dupree: She had it all. Style, grace, ethereal beauty. Just like I thought Mandy did.
Molly Peterson: I don't know. I have a hard time imagining Audrey Hepburn getting buttered up to Funky Cold Medina.
Dupree: Really? I don't.
Carl Peterson: It's not like I'm going to be working for him for the rest of my life. You know, I got plans of my own.
Dupree: There it is. There's that Carlness. They can't lay a glove on you, can they? God, I admire you. I really do.
Carl Peterson: Make yourself at home. Molly and I are... Well, we're going to go upstairs and take care of some stuff.
Dupree: Well hey, hey, hey, hey. Listen, we're all adults here. You're newlyweds. Making love's a big part of that. You're supposed to explore each other. I get it. Come on. If this situation's gonna work, we've got to be honest with each other. Now, go on. Enjoy yourselves. I'm not going to listen. Hump away. Go on, get out of here. Good night.
Carl Peterson: The insurance adjuster recommended that we sue Dupree.
Molly Peterson: For a mooosehead?
Dupree: I'm throwing seven different kinds of smoke!
Carl Peterson: [Carl is rubbing Molly's feet] You have the most beautiful toes, have I ever told you that? And I'm not even a foot guy.
Molly Peterson: Are you concentrating on the game? Or are you lusting at the feet of your soon-to-be wife?
Neil: [watch beeps] Shit balls!
Carl Peterson: What's that?
Neil: It's my alarm. My hour's up. That's it for me.
Carl Peterson: What, are you kidding me? Where are you going?
Neil: I've got to go meet my wife and watch Sisterhood of the Traveling Ya-Ya Pants. I don't... How late do you get to stay out? I used to have midnight. Do you get midnight? 'Cause I was late once...
Carl Peterson: I'm a grown man, Neil. I don't have a curfew.
Neil: Not yet you don't.
Carl Peterson: [choking Dupree] Poetry, Aunt Kathy, librarian-banging, backstabbing, bike-riding, couch-burning masturbator! You ruined my life! You ruined my life!
Dupree: Listen, if I got to be the lovable fuckup all my life to win your best friend prize, maybe you should keep your award.
Carl Peterson: I got news for you Dupree. You're not that lovable.
Carl Peterson: He's never truly been domesticated. He's like the ape-man of Borneo.
Carl Peterson: What's going on with you and Molly?
Dupree: What?
Carl Peterson: You heard me. Are you in love with my wife?
Dupree: Have you lost your mind? What are you talking about?
Carl Peterson: Dupree. Dupree, just answer the question.
Dupree: Whoa, hold on, Jake LaMotta. I'm not gonna answer... that's a sick question!
Carl Peterson: How come you can't answer it?
Dupree: I'm not going to answer because it doesn't deserve and answer. How could you ask me something like that?
Carl Peterson: You're very clever, Dupree. You're living in my house. You're going to town on yourself in my living room. And now, you're moving in on my wife.
Dupree: What?
Carl Peterson: You think you got it all figured out, but I'm on to you, and you're out of here!
Dupree: Oh, no. Hold on. You're not throwing me out of here. I'll leave!
Carl Peterson: Good! And while you're at it, leave the flask and the groomsman's outfit.
Dupree: But you gave those to me. Those were gifts.
Carl Peterson: All right! You know, keep those. But leave the insignia, because that was for my best man.
Neil: [breathes in Carl's face] Do I smell like beer?
Carl Peterson: Yeah.
Neil: Good. Because you know what I don't smell like, then? Cigarettes and weed.
Molly Peterson: You haven't really been taking care of yourself. I can't remember the last time you exercised. And how many Twinkies have you had today?
Carl Peterson: What are you talking about?
Molly Peterson: Oh Carl, please. There's like a million Twinkie wrappers on the floor of your car. You're not fooling anybody.
Carl Peterson: All right. All right. So I admit it, I enjoy one occasionally. Is there something so wrong with that? Look, Molly, I am under a great deal of stress! What do you want from me?
[spots a magazine with Nick Lachey on the cover]
Carl Peterson: Wait a minute. Is this the kind of thing that turns you on?
Molly Peterson: Oh, Carl!
Carl Peterson: Is this what turns you on? Come on, Molly!
Molly Peterson: I was reading an article on Oprah!
Carl Peterson: Yeah, well I'm sorry I can't be one of your boy-band flavor-of-the-weeks, with their enhanced frosted tips and washboard bellies and their hairless backs!
Molly Peterson: What's happening to us, Carl?
Carl Peterson: I don't know what's happening to you, Molly, but apparently I'm getting fat!
Molly Peterson: Did you know Dupree writes poetry?
Carl Peterson: What a homo.
Carl Peterson: What's with this "Carlness?" It's not even a real word.
Dupree: Yes it is.
Carl Peterson: Oh, it is?
Dupree: It's a verb. It's a conjunction. A preposition. It's a philosophy. A way of life. It's your name with "ness" attached to it.
Molly Peterson: Look at that. It's my grandmother's silver cheese platter and you used it to serve nachos.
Carl Peterson: Well nachos have cheese in them.
Carl Peterson: If you're going to stay here, things are going to be different from now on. No more naked stuff.
Dupree: But it felt natural to be naked...
Carl Peterson: I don't care! I do not care!
Carl Peterson: Everybody knows that your father, when he likes somebody, he invites them out on a little fishing trip. Fact: I've never been invited fishing. Not once.
Molly Peterson: You hate fishing.
Carl Peterson: He doesn't know that.
Carl Peterson: Why don't you watch it in your house?
Neil: Because I can't have friends over on weeknights and you know that.
Neil: Don't tell me you want the porn back because you can't have it! Why is it all Asian?
Dupree: [during his job interview] I'm a people person, very personable. I absolutely insist on enjoying life. Not so task-oriented. Not a work horse. If you're looking for a Clydesdale I'm probably not your man. Like I don't live to work, it's more the other way around. I work to live. Incidentally, what's your policy on Columbus Day?
Interviewer: We work.
Dupree: Really? The guy discovered the new world. I'm afraid to even ask about Victory Over Japan Day.
Dupree: FirstFirst of all, thank you for giving me the opportunity to come talk to you on Career Day. Now, I am not Mr. Carl Peterson and I don't have a career per se. I guess you could say my career is living and loving. And I do that to the utmost... I see all you fresh-faced kidlets sitting there in your neat little rows, and you're all just pods. Pods, waiting for your instructions. Now some of you are going to get zapped right away and be 15-year-old prodigies, little midget Olympic gymnasts with their pictures on cereal boxes. Some of you will go on to college, and you'll find your rhythm there and then go chase down the titans of industry, or maybe straighten out our problems at the UN. But some of you, and this is the group that no one ever comes into Career Day and addresses, and it's criminal! Some of you are just going to float along, eating spicy foods, humming black people's music into your 30s, well into your 30s, languishing. This group of pods is going to do a lot of languishing. And you're going to take some heat for it. Sadly, you will. Europe's a little easier. They seem to understand a little better. So does South America. I went to Argentina one time and everyone just seemed to be sitting around. It was beautiful. But that's okay. Stay loose. Stay liquid. Laugh a lot. But be ready. That's what Dupree's doing with his life's little pod. Staying nimble till I get the call from the mother ship. My raison d'état. Then I'd fight. Then you'll see Dupree coming in here throwing seven different kinds of smoke!
Molly Peterson: Now you've upset Randolph.
Carl Peterson: Randolph? Randolph? You've got to be kidding me. I know a Randy Dupree. I do NOT know a Randolph!
Molly Peterson: Did it ever occur to you that maybe he prefers to be called Randolph?
Carl Peterson: No, Molly, it never occured to me. The guy writes some bullshit poetry, and suddenly, he's got a brand new name.
Carl Peterson: Would you be offended if Thompson asked you to get a vasectomy?
Dupree: [exasperated] What? Why would he want me to get a vasectomy, Carl? I barely know the man!
Carl Peterson: Sshhh, wait a minute! Wait! Dupree...
Dupree: Yes, I'd be offended!
Carl Peterson: No, not you! That's not what I mean! Just what do you think of vasectomies?
Dupree: Cutting off my manhood? I think it's barbaric. No one's getting near that part of my body. No one, Carl. Unless, of course, it's a woman. And then she better not have a scalpel.
Carl Peterson: Of course.
Dupree: Why would he want me to get a vasectomy?
Carl Peterson: He doesn't want you to get a vasectomy. It was a hypothetical question.
Dupree: Okay.
Carl Peterson: Forget I asked.
Dupree: Don't joke with me like that, man.
Toshi: But, Mr. Dupree, I don't play baseball. I'm in the orchestra.
Dupree: First, call me Dupree 'cause I'm your teammate. Second, so what if you're in the orchestra? So was Catfish Hunter.
Carl Peterson: You gonna hit me with that thing? Come on I dare you!
[Thompson knocks him out with a candlestick]
Molly Peterson: Dad!
Mr. Thompson: He dared me.
Neil: How the hell did Dupree wind up on the worng island?
Carl Peterson: Dupree was born on the wrong island.
Mr. Thompson: [giving a toast] Now when Molly told me that she was going to marry Carl, I said "Who?" She said "Daddy, he works for you." I said, "Honey, I've got 1,200 employees nationwide." But then, I started to worry. Maybe he was some young buck trying to push me aside, grab the reins of my company.
[smiles]
Mr. Thompson: And then I met Carl, sitting in cubicle 26. And I said, "You know, I like my chances."
Neil: You cannot come in here. She said so, man. She makes the rules.
Carl Peterson: You know what? I don't need this, Neil. I don't need this.
Neil: I don't need this! I'm sorry!
Annie: Neil, get back in here!
Neil: She controls what I do!
Randy Dupree: Everyone's asleep and here's lonely old Dupree waling away on himself.
Molly Peterson: You weren't waling away...
Randy Dupree: God! An animal wouldn't debase himself thus!
Dupree: Bob, before I go, I have my own question for you. And remember, you've never lied to me either, as far as I know. Who did you really want to get a vasectomy? Me? Or was it, in fact, Carl?
Neil: [on the phone with Carl] Did you actually throw away your porn collection?
Carl Peterson: Look, Neil, I'm having a dinner party.
Neil: I'm coming to get it.
[yells to his wife]
Neil: Going to Starbucks! Be back!
Dupree: So what if her dad hates you. You think you're the first guy to be hated by his father-in-law? So what if he beat your ass with a candlestick. That's probably happened before.
Dupree: There really aren't any more Audrey Hepburn's out there, are there?
Lance Armstrong: [Very last lines after the credits]
[Having just read Depree's book and breaking the forth wall]
Lance Armstrong: Lanceness Lance... ness? Lancennneeesss LanceNess
Molly Peterson: Dad, I'm going to ask you something and remember, you've never lied to me before. Do you ever really want my marriage to work?
Mr. Thompson: That's a really complicated question, Molly.
Molly Peterson: No. Actually, it's not.
Carl Peterson: You've done everything you can to undermine me. You've tried to intimidate me. You've tried to humiliate me. You've bastardized my project to the point where it's unrecognizable. But here's the thing, Bob. I don't care. I don't care about this job, and I don't care about you. I care about Molly! She means everything in the world to me. And if you're going to stand in the way of me trying to win her back, you'd better bring a pretty big candlestick.