吃不到葡萄说葡萄酸追不到你说你像二愣
[chī bù dào pú táo shuō pú táo suān zhuī bù dào nĭ shuō nĭ xiàng èr lèng]
It's derived from an old Chinese idiom 'eating-the-grapevine-vinegar' (sour grapes). This phrase implies that someone who can't have what they desire might criticize it, suggesting a form of rationalization. Here, it adds humor by implying giving up pursuing a romantic interest and criticizing them playfully.