Actress Alia Bhatt said her husband, actor Ranbir Kapoor, learnt how to sing the Malayalam lullaby 'Unni Vava Vo' for their daughter Raha. "Our nurse has been singing 'Unni Vava Vo' to Raha since she was an infant," Alia said at 'The Great Indian Kapil Show'. "Ranbir and Raha's relationship is one for ages...There is friendship between them," she added.