我非柠檬为何你心会酸
[wŏ fēi níng méng wéi hé nĭ xīn huì suān]
Literal translation: 'I'm not a lemon so why do you feel sour?' It could be a metaphor for jealousy or bitterness in a situation, often used humorously. The reference here may suggest that despite the user not being in a position to evoke these emotions (like jealousy), someone feels bitter anyway.