因为你傻得无可救药
[yīn wéi nĭ shă dé wú kĕ jiù yào]
Yīnwèi nǐ shá de wú kě jiù yào translates to 'because you are incurably silly' or 'because you are hopelessly stupid,' often used humorously, expressing someone's endearing or amusing naivety or foolishness.