Newlyweds Carl (Dillon) and Molly Peterson (Hudson) have just moved into their new house. One night, stopping at a bar, however, Carl catches his best friend; the childish, immature, free-spirited Randolph "Randy" Dupree (Wilson) languishing around. It turns out that because Dupree did not have leave to attend Carl and Molly's wedding, he lost his job, was thus unable to pay his rent, and is now homeless. Carl allows him to stay and his and Molly's new house until he gets back on his feet.
Almost immediately, Dupree is annoying the hell out of them both and when Molly tries to hook him up with Mormon librarian Mandy; they come home to find him having sex with her in their living room using butter as lubricant, after which their couch ends up set on fire. Finally, they can stand it no more and throw him out.
After finding Dupree out in the rain, they let him back in again, but insist he gather his act together. He complies. Alas, Carl is starting to drift away, crushed by pressures at work pertaining to his boss/father-in-law Bob Thompson (Michael Douglas), who despises him. The lonely Molly gets to know the freshly-reformed Dupree, and Carl begins to suspect they're having an affair...
Didn't do well with critics (21% on Rotten Tomatoes), who considered it flat and cliched, but was a relative box office success.
This film provides examples of:
- Caught with Your Pants Down: Carl and Molly catch Dupree on A Date with Rosie Palms in their living room to a porno movie. Unfortunately, Dupree hadn't put away a box labeled "camping gear" where he got the tape from which contained Carl's entire collection of Asian porn movies, which Molly promptly forces him to toss.
- Calling the Old Man Out: Carl, Molly and Dupree all do this to Molly's father Bob, who's been passing out all sorts of hints that he doesn't like Carl and has sought to undermine him, near the end of the movie.Carl: 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.
- Dating What Daddy Hates: Mr. Thompson does everything he can to undermine and emasculate Carl at every turn. It doesn't help that he is also his boss.
- Deconstruction: While it's broadly sympathetic to him, as Roger Ebert noted in his review the movie nevertheless points out that, despite their popularity as movie comedy characters, goofy, immature and self-centred Manchild party boys like Dupree who keep finding ways to cause Wacky Fratboy Hijinks and become The Thing That Would Not Leave become pretty insufferable pretty quickly if you have to put up with them on a regular basis in real life. At one point, Dupree complains about how everyone only sees him as the loveable fuck-up, only for Carl to angrily shoot back "I got news for you: you're not that loveable."
- Drowning My Sorrows: How Dupree finds Carl after he snaps, beats him and runs away.
- The Faceless: We never see Mandy, Dupree's girlfriend Molly sets him up with.
- Five-Temperament Ensemble: Dupree (leukine), Bob Thompson (choleric), Carl (melancholic), Mandy (phlegmatic), and Neil (sanguine).
- Friend to All Children: Dupree. When Carl runs off, the kids try help Dupree to find him.
- Fun T-Shirt: Dupree wears a t-shirt with a picture of a gnome and the caption "Say Hello To My Little Friend."
- Hand-or-Object Underwear: Dupree holds two small pillows in front of his crotch and butt after Molly catches her having sex with her friend.
- Hidden Depths: Molly starts taking a liking to Dupree when she sees beyond his party-boy persona and sees a kind, talented, hopeless romantic of a man.
- Interrupted Intimacy:
- Dupree keeps interrupting Carl and Molly whenever they try to get intimate in their own room.
- Molly accidentally walks in on Dupree and one her friends having sex.
- Manchild: Dupree is extremely immature for his age, and treats life like a big party. He even makes friends with kids from the block.
- Mean Boss: Mr. Thompson enjoys making rude jokes about Carl in public and goes out of his way to try to undermine in at work, mostly because he doesn't approve of him dating his daughter.
- Mistaken for Cheating: Carl thinks Molly and Dupree might have an affair due to her being nice to him and her father liking Dupree more than Carl.
- Multi-Character Title: The film is named after the three main characters, from Carl's point of view: "You (Molly), Me (Carl) and Dupree"
- Professional Slacker: Dupree won't take any job that doesn't have Columbus Day and Victory Over Japan Day off.
- Sex Goddess: Mindy, the Mormon librarian Molly sets up Dupree with. Molly thinks her being a Mormon means she will be chaste, but she catches them both having kinky sex after their first date, with Dupree personally thanking Molly for "the best time of his life". We later find out the librarian Really Gets Around and is sleeping with half of the faculty.
- Shipping Torpedo: Mr. Thompson can't wait to get rid of his son-in-law.
- Sleeps in the Nude: Carl and Molly find Dupree sleeping naked on their couch, much to their disgust.
- The Thing That Would Not Leave: Carl regrets having Dupree moving in with them almost immediately, as he makes life for Molly and Carl a living hell. Dupree sleeps naked on their couch, changes the message on their answering machine, gets cable for their TV without their permission, walks in on them when they're about to have sex and messes up their toilet.
- You Taste Delicious: Carl has a nightmare sequence with Molly in a bikini suggestively licking Dupree's face.