Hadh Kar Di Aapne (2000)

Anjali Khanna had always suspected her husband, Sanjay, of cheating on her, and flirting with other women. In order to keep an eye on him and his activities, she asks her friend, who is also named Anjali Khanna (Rani Mukherji) to go abroad under her name, which she does so. When Sanjay finds out that Anjali to go abroad, he hires Raj Malhotra to follow Anjali and make sure she is not having an affair, Raj does so with hilarious results.