做你的小火车永远不出轨做你的美人鱼永远不出轨
[zuò nĭ de xiăo huŏ chē yŏng yuăn bù chū guĭ zuò nĭ de mĕi rén yú yŏng yuăn bù chū guĭ]
Translates as 'Be your little train that will never go off track; Be your mermaid who will forever be true and never go astray.' These two sentences express loyalty and fidelity in love through metaphorical ways, using both fairy tales and everyday images, promising never to be disloyal, emphasizing commitment and dedication.