Yeah basically he’s just being an asshole and messing with her. Then again if I were to play devils advocate it might also be that if it becomes openly realized by his mom she’s a penguin she could get kicked out (unlikely) or more likely that would get back to the dad and she would leave.
Idc about anyone but her dad. Also why doesn't suradel tell her he knows she a penguin? Does he like her being anxious? What an asshole