感谢你让我成为不再爱笑
[găn xiè nĭ ràng wŏ chéng wéi bù zài ài xiào]
It stands for 'Thank You for Making Me Stop Smiling'. This implies a complex emotional history. It suggests the person had a painful experience with someone which has changed their personality or mood significantly, leading them to less joyful and more reserved.