你是我的小番薯你是我的小芋头
[nĭ shì wŏ de xiăo fān shŭ nĭ shì wŏ de xiăo yù tóu]
This nickname expresses deep affection towards someone, addressing them as 'sweet potato' and 'taro', both are beloved edible plants which could represent cuteness and fondness in Chinese culture.