我好想你隐藏在心里我好想你就当做秘密
[wŏ hăo xiăng nĭ yĭn zàng zài xīn lĭ wŏ hăo xiăng nĭ jiù dāng zuò mì mì]
This expresses strong hidden love and longing for someone which remains unspoken. Translated to 'I miss you so much; this feeling hidden within my heart, kept as my secret'.