我爱他三年如梦他爱我三年如戏
[wŏ ài tā sān nián rú mèng tā ài wŏ sān nián rú xì]
The user conveys that his/her love for someone lasted three years and felt like a dream, whereas their reciprocal affection felt insincere or playful, implying the bitterness of unrequited love over an extended period.