过去与你未来与你
[guò qù yŭ nĭ wèi lái yŭ nĭ]
It means both 'the past with you, and the future with you'. With this user name, the speaker wants to emphasize the importance of a specific person (usually a partner) throughout different periods of their life, implying an eternal relationship or wishful thinking. This suggests the importance of someone through the continuity and span of time from past and to future.