当年的承诺现在化为泡沫
[dāng nián de chéng nuò xiàn zài huà wéi pào mò]
This nickname expresses the idea that past promises made by someone (usually ex-lovers or friends) have turned out to be unfulfillable, like a beautiful dream that finally bursts and disappears as quickly as foam in water. This implies some sense of sorrow and helplessness.