At Waterloo station in London, two strangers, Rikki Thukral (Abhishek Bachchan) and Alvira Khan (Preity Zinta), wait for their respective fiancés. Rikki is a fun-loving Punjabi boy from Bhatinda who lives in Southall, while Alvira is a middle class Pakistani girl from Lahore who is more assimilated into British culture. The two share a table in a cafe together and to kill the time they talk about how they met their partners-to-be.
Rikki, handsome but primitive in the desi way, says that he met his fiancé, Anaida Raza (Lara Dutta), at the Hôtel Ritz Paris, the same night that Diana, Princess of Wales and Dodi Al-Fayed left the hotel to take their last journey together. Rikki explains “When two lovers die, another two are born”, as he fell in love with Anaida that night. Alvira says she met her fiancé, the dashing lawyer Steve Singh (Bobby Deol) at Madame Tussauds in London when he saved her from death by a falling Superman wax model. The encounter changed her life and she was smitten by the lawyer who also helped her sue Madame Tussauds for substantial damages.
As Rikki and Alvira talk they begin to enjoy each other’s company and their different backgrounds cease to matter. They exchange numbers and go to meet their partners. However, it is then revealed that they had not gone to meet their respective partners. Rikki is in fact at the train station to meet his business partner, while Alvira is meeting her relatives. As they leave the station separately, they realize they are in love, but believe their love is unrequited, each of the other.
The two get in touch when Alvira calls Rikki, pretending it was a wrong number. They decide to meet up at a disco where there is a dance competition but both try to maintain the fiction that they are engaged. Out of desperation, Rikki hires Laila, a prostitute, to pose as Anaida, and Alvira asks Satvinder — a mummy’s boy/optician — to pretend to be Steve (these characters are played by Dutta and Deol, the same actors that played their fictional lovers). The four meet at a club and take part in the dance competition, while throwing insults at each other. Rikki and Laila emerge as the winners but Alvira is jealous and storms out in tears.
Satvinder goes to Rikki’s flat and tells him that he has fallen in love with Laila. He also tells him that Alvira is not engaged to him. Rikki, realising what has happened, goes to see Alvira, who is at first moping in bed and later tries to convince her cousin not to marry her. Rikki calls her from a neighbor’s window. The two meet in the street and declare their love for each other, sealing it with a long kiss.