Wei Daxun said, "Piaodai, you are so bad." In English, it can be translated as "Piaodai, you are very naughty." Or "Piaodai, you are rather mischievous."
This expression might imply that Piaodai has done something that Wei Daxun finds a bit unruly or not so proper. It could be a playful reproach, showing a lighthearted interaction. Maybe Piaodai played a prank or did something unexpected that made Wei Daxun react in this way.
The tone is likely not overly harsh but rather affectionate and humorous. ????