She kept referring to her co-star Nawazuddin Siddiqui as bhai (brother) during the shoot even though he's playing her love interest in the film! It used to be okay until they would shoot romantic sequences.
It was at those times that everybody used to burst out laughing.
Huma tells CS, "Yes, I address Nawaz as brother out of respect and even during intimate scenes, I kept calling him so. Needless to mention, all the folks on the sets ended up laughing at my expense."