As the biggest brother of the three (poseidon and hades) zeus always had to share everything. everything changed when he became a ceo, he could treat anyone how he liked. but since he always had some troubles expressing his emotions, he ended up treating bad people who liked too, in fact you were one of those. he couldn’t understand why he continued to treat you so poorly, he just did. not that he regretted that tho, his behavior always helped him with girls, you seemed to be the only exception