Vishnu Trivedi, Vinay Pathak is a faltering politician in the small town of Mathura who campaigns to ban live-in relationships, viewing them as a stain on Indian traditional culture. At the same time, his party targets film star Nazeem Khan, Abhinav Shukla who is alleged to be in a live-in relationship with his girlfriend, fueling Vishnu's ongoing grudge against modern relationships.
Rashmi Trivedi begins an internship at a local news channel and teams up with the channel's star reporter Kartik Aaryan as Vinod "Guddu" Shukla, and his best friend, Aparshakti Khurana as Abbas Sheikh. Guddu and Rashmi fall in love, and Guddu proposes, but Rashmi is not ready for marriage and suggests a live-in. He, more traditional and wary of Vishnu's reaction, hesitates. As a compromise, Abbas suggests trying a live-in during their 20-day business trip to Gwalior, and the couple agrees.
They rent an apartment in a conservative area by pretending to be a married couple. As they grow closer, they consummate their relationship. Their nosy neighbour, Mrs. Shrivastava, Sapna Sand, grows suspicious when she spots them. To complicate matters, they give mixed answers about their wedding date, which only fuels her doubts.
To head off the neighborhood uproar, Guddu and Rashmi fabricate photographs and wedding mementos overnight, sidestepping Mrs. Shrivastava's plan to gather the locals the next morning. By the end of the twenty days, Guddu reaffirms his love and Rashmi accepts his marriage proposal. Before they can leave Gwalior, Guddu's relative Babulal, Pankaj Tripathi, spots them together, tails them, and sees the wedding pictures, jumping to the conclusion that they have eloped.
The next morning, Babulal brings Guddu's entire family to Rashmi's house and they chasten him for eloping. Realizing the family would accept a marriage but not a cohabitation, the couple does not reveal the truth. They return to Mathura to meet Rashmi's family, while Vishnu is pleased to hear that his daughter has chosen marriage over cohabitation, even warning of the harsh consequences if they had lived together.
Although they begin living like a married couple, they resent not being legally married. They make several attempts to wed in secret, but they are interrupted each time; in a last-ditch effort, they participate in a mass marriage event, only for Vishnu, as the chief guest, to catch them red-handed. Exasperated, they admit that they had been cohabiting.
Guddu then confesses to Vishnu that the main reason for his electoral loss is the elder's reluctance to change, since the majority of voters are younger and favor modernity. He convinces Vishnu to stop opposing live-in relationships, and the two eventually bless Guddu and Rashmi's marriage.
The story ends with Guddu and Rashmi reporting on a rally led by Vishnu, who is shown to have joined Nazeem Khan's election campaign.
