掏心喂狗狗不理
[tāo xīn wèi gŏu gŏu bù lĭ]
This implies feeling undervalued or unappreciated. The literal meaning of 'offering one’s heart to dogs who won’t even acknowledge it,' conveys that no matter how much effort or sincerity the user shows toward someone, it goes ignored or is unappreciated by that person, like food offered to a dog being ignored.