我将来要闹你的婚礼请不要闹自己的婚礼
[wŏ jiāng lái yào nào nĭ de hūn lĭ qĭng bù yào nào zì jĭ de hūn lĭ]
It means 'I'll ruin your wedding but don't do the same to your own.' The first part conveys a playful promise (or threat) while the latter serves either humorously as self-reminder about behaving better.