Characters proximity felt a bit forced without us seeing their background. 
Also have you ever met any teachers ever? as a teacher let me tell you the whole pranking thing might happen once or twice but we got way too much shit to get done to have time for it and it made me so stressed at how unreal it all felt.
Also I really really think the way Ilsa talked to Andry about her ex was very much ??????? like that's just not the right take.