一时为你动情一世为你守情
[yī shí wéi nĭ dòng qíng yī shì wéi nĭ shŏu qíng]
It conveys an emotion of love where at one time the person falls in love with someone ('falling in love' phase) and spends all life cherishing those feelings. Translation: Once I was stirred by your affection, forever I will be loyal to this sentiment. It depicts true love from beginning to end, showing the constancy of love over lifetime.