The film opens with two cousins – Heena (Asin Thottumkal) and Bobby (Jacqueline Fernandez), the two daughters of the Kapoor family who hate each other very much – start quarrelling over something relating to their duties of Animals’ Law Authority. Their fathers, Chintu (Rishi Kapoor) and Dabboo (Randhir Kapoor), are step-brothers who hate each other to the very core. Even their wives hate each other. Chintu wants the richest son-in law for his daughter, Heena, while Dabboo too wants the same for his daughter, Bobby. Aakhri Pasta (Chunky Pandey), a marriage counsellor, is ordered by both Chintu and Dabboo to find the best son-in-law. Aakhri Pasta brings Mr. Babani (Virendra Saxena) to discuss Babani’s son Jai.
When Chintu misinterprets one of Aakhri’s comments, who says that Jai looks neither like his mum or dad and may be a step child. Mr and Mrs. Babani did not hear Aakhri’s comments and Chintu verbally abuses Babani while shouting. Babani suffers from a condition that affects his heart when he hears loud noises. Due to Chintu’s shouting, Babani suffers a heart attack, landing him in a hospital. Babani’s son Jai (Shreyas Talpade) comes to know of this and gets angry, then vows revenge, telling his friend Jolly/Jwala (Ritesh Deshmukh), who is the son of billionaire J.D. (Mithun Chakraborty), to go to Chintu, agree to marry his daughter and then break off the wedding at the last minute. Jolly is busy trying to introduce his girlfriend Jlo (Zarine Khan) to his own father and does not want to get involved. He suggests Max (John Abraham), their former college mate and a pick-pocket, to do the job. Jay goes with Max as his driver but somehow, they end in the wrong house and go to Dabboo’s house.
Jay and Max later find out their mistake. Jai, still wanting revenge, doesn’t know what to do and Jolly suggests another former sleazy college mate, Sunny (Akshay Kumar). Jolly goes with Sunny as his bodyguard because Max and Sunny are sworn enemies and as Dabboo’s house and Chintu’s house are right next to each other, their plan may get destroyed. Sunny and Jolly encounter a crocodile and Max and Jay encounter a snake each of the girls has as their pets. They manage to survive the attack.