While near, 50 heroes have been habitually romancing girls less than half their age on screen, the reverse trend seems to be catching on in Bollywood now. Actresses are being paired opposite younger actors, too. Commercial cinema no longer considers it a taboo for an older actress to court a younger actor on screen. There have been the stray instances in the past, of course.
In the '70s, Zeenat Aman played lovergirl to Rishi Kapoor, a year younger than her. Akshaye Khanna had a love track with Dimple Kapadia in Dil Chahta Hai but that was owing to demands of the script. Aishwarya Rai romanced Vivek Oberoi in Kyun...Ho Gaya Na, and Abhishek Bachchan in Dhai Akshar Prem Ke and Kuch Na Kaho. While Vivek is three years younger, Abhishek, who she subsequently married, is younger by a couple of years. These, though, were exceptions. The trend seems to be catching on now.