You, Me, and Dupree: Owen Wilson Stars as Houseguest from Hell

Molly (Kate Hudson) and Carl (Matt Dillon) are happy newlyweds until Carl's friend Dupree (Owen Wilson) becomes their houseguest from hell. Dupree has no place to go, having lost his job and apartment and even his car. Carl promises Molly that it will only be a couple of days, but the days stretch on and Dupree is still there, causing tension between Molly and Carl. 

Dupree orders HBO without consulting them, doesn't pick up after himself, and seems to prefer to skateboard with the neighborhood kids rather than look for a job. The last straw for them occurs when Dupree nearly burns down their house. Carl asks him to leave, and Dupree agrees, figuring that he will stay with Mandy, the librarian Molly set him up with and whose face the audience never actually sees.

After one date, Dupree believes that Mandy is the love of his life. But then driving home in the pouring rain after a night out, Carl and Molly drive past Dupree, shivering on a bench, having been dumped by Mandy. Molly takes pity on Dupree and insists on letting him stay with them again. Carl reluctantly agrees, but tells Dupree he needs to help out around the house. Dupree takes this to heart and cleans up the house, which hadn't yet been cleaned up after the fire. As it turns out, he is also a good cook and he starts cooking some meals for them. 

Meanwhile, Carl is under increased pressure at work. He works for his father-in-law (played by Michael Douglas). When he and Molly got married, he was given a big promotion, but then his project is changed so much that it bears little resemblance to his original idea. 

On a more personal note, his father-in-law tries to convince him to (a) take Molly's name instead of Molly taking his, and (b) get a vasectomy. Carl starts to get the idea that his father-in-law doesn't much care for him. His work also keeps him away from home a lot. Molly and Dupree become friends, and Carl starts getting suspicious, fearing that Dupree is after Molly. Actually, though Dupree can be annoying, Carl's father-in-law seems to pose the tougher challenge.