So she notices that some days he comes to the set blank-faced and doesn’t say a word to anyone and some days he has this big ridiculous grin on his face and he laughs (too hard) at everything she says.  Suji has her suspicions about what that means, but it she isn’t one to pry, so it takes a couple of weeks before she gets to confirm things.  Myungsoo and Suzy get cast in the same drama and end up having a conversation Suzy hadn't anticipated.