Plot

A young couple in London struggle to live with their estranged aunt and uncle, who overstay their welcome.

The film is a comedy revolving around Aryan (Kartik Aaryan) character, who is in a live-in relationship with his girlfriend in London, Anaya (Kriti Kharbanda) when his Chacha (Paresh Rawal) and his wife Chachi (Tanvi Azmi) barge into his home as guests, setting off a laugh-riot.

Anaya is doing the live in with Aryan, to prove to the court that they love each other and that they are allowed to be married. In fact Aryan is paying Anaya 7000 pounds to help him get his UK citizenship. In the middle of all this, as Aryan is trying to plan a fake wedding, Gagga Chacha and Guddi Chachi descend upon his life as a plague. Aryan's real Chacha calls him from India to say that Gagga is the tenant of their neighbor in India.. Aryan has no choice but to host them and to put up with them.

Anaya reacts when Chacha Chachi demand that she has to dress properly in the house. They are shocked to find that Aryan & Anaya are getting married in 10 days time. The court appointed observer is a Pakistani, who takes up residence next to Aryan and keeps making random visits to ascertain is the wedding is genuine. Things are going mixed. Aryan and Anaya love the food cooked by Chachiji and ask them to stay longer. However now Chachaji insist that Anaya should sleep with Chachi and he sleeps with Aryan. They also commit them both to community service at the local Gurdwara.

As the intrusions grow, things grow beyond breaking point, but the fear of being caught out keeps Aryan and Anaya from retaliating. Finally the day of the wedding arrives and Chacha insists that they get married in a Gurdwara and not a registrar's office. Post wedding Chachiji counsels Anaya on the virtues of staying together & slowly Anaya falls in love with Aryan.

Aryan's boss Mr Kaalia invites Chachaji as a special guest to a office party. Chachaji stops Kaalia from hitting on a Chinese girl who works for him. Things get out of hand when Kaalia accuses Chachaji of misbehaving with the Chinese girl. Aryan intervenes, but he, Chacha, Chachi and Anaya are expelled from the party. Aryan is fired from his job, but he refuses to sacrifice Chachaji's honor for it. Aryan and Anaya, now in love and married, want to have sex, but Chacha and Chachi keep coming in the way, without knowing. Then one day one of Chacha's drinking buddies passes away in his sleep. Chacha refuses the coroner's ambulance and organizes an Arthi, through the streets of London. He is arrested for not having a license. Anaya is furious as this costs another 500 pounds to bail him out. Since Chacha is offended by small clothes, Anaya organizes a hens party at her house with all her friends in skimpy clothes. But Chachaji accepts this & refuses to be offended by this.

One day Aryan sees Chacha & Chachi meeting a Muslim guy on the street, while lying that they are sightseeing in London. He is suspicious & looks through his luggage to find photos of Chacha and Chachi in Al-Qaeda garbs. Aryan and Ayana are shit scared and Aryan calls the police to tip them off that Chacha's visa has expired. At the police station Chacha reveals that Chachi's real name is Sazia Khan.

Chacha returns home the same evening. Now Aryan and Ayana make a plan to abandon Chacha and Chachi on the way, while taking them on a trip to Scotland. while Aryan is executing the plan, Ayana finds a package that has arrived for Chacha and tickets for Chacha and Chachi to return to India. Aryan's battery goes dead and he cannot receive Ayana's frantic calls to him. After coming home, Aryan finds a bunch of files in the package and a sudden deposit of 100,000 pounds in his account.

Aryan and Ayana meet the sender of the package (which came from London). The sender tells Aryan that Chacha and Chachi had a son who worked in London and who was killed in the 9/11 attacks on a trip to NYC. Chachi had a stroke and recovered after 8 yrs. Then they came to London to collect his stuff. They waited as Aryan was having a wedding and they did not want to spoil anyone's mood. Finally, they asked the sender to courier their sons's stuff to Aryan's house & the tickets to NYC, where Sazia wanted to read a last Namaz for her lost son at ground zero. The lost son had an insurance, which Chacha said should be transferred to Aryan's account.

Aryan and Ayana rush back, but Chacha and Chachi are nowhere to be seen (they hitched a ride back to London). Aryan and Ayana only find Chacha and Chachi at ground zero, where Chachi is performing her last Namaz for her dead son. They reconcile and Chacha and Chachi return to India. They come to London again when Ayana is pregnant with twins.