I'm not suprised if Shyam accidentally spill the beans to Anjali maybe in anger mode...as you know, there's so may incidents where he was mentioning to Anjali about certain things which was she herself find pretty fishy about it...do remember what Anjali told her brother, Arnav that she has a detective around her...maybe without we knowing actually Anjali knows what was happening between her chote, Arnav, Khushi and Shyam...she know that Arnav loves Khushi but her hubby is the one creating the MU between all of them but I guess she's the type of person who prefer true confession rather than jumping to conclusions...