The designer duo has been creating outfits for the Bachchan family - Amitabh, Jaya, Abhishek, Aishwarya and Shweta Nanda - since long, and their association goes much beyond just clothes. Amitabh recently launched their book in London, along with Hollywood star Judi Dench.
As for the much awaited birthday bash, Khosla remained tight-lipped, but said: "It will be Jaya Bachchan's event. We will only be helping her with all the preparations. Individually, we are not hosting any party for him."