Actress Sonam Kapoor has apologised to actor Amitabh Bachchan on Twitter for not replying to the sms he sent her on her birthday. Big B, while replying to a tweet where Sonam thanked Suniel Shetty for his birthday wishes, had written, "and what about ME... this is Amitabh Bachchan my dear." Sonam clarified that she missed seeing Bachchan's message.