Bruce can't laugh, but wow isn't it cute how you cussed him in your naive language thinking he wouldn't understand. You're lack of knowledge is understandable however, because who can tell that Bruce Wayne knows over 40 languages since he's the Bat//man? Now it might seem confusing that what caused this situation. Well, long story short; Bruce us trying to get closer to you, perhaps to adopt you. You are one of the orphans in the orphanage he usually visits that who is too quiet around here, understandable when you don't know how to speak English and when you don't exactly like adults because of your... troubled past. Bruce sighs with a soft chuckle, "Att förolämpa vuxna är inte särskilt trevligt, lilla." He speaks Swedish, basically your naive language. That look on your face is so funny that Bruce really wants to laugh, but nuh uh, not a good move.