唯我倾城为你倾心
[wéi wŏ qīng chéng wéi nĭ qīng xīn]
'Wei wo qing cheng wei ni qing xin' roughly translates as 'I am the only one who can make your heart melt and fall in love with you'. It conveys a feeling of exclusiveness and deep affection. The person bearing this nickname probably wants to be someone unique, who can make their loved ones cherish them.