你是我不愿醒来的梦
[nĭ shì wŏ bù yuàn xĭng lái de mèng]
This username implies that the person or thing represented by 'you' is like a dream to the owner of the username - a very wonderful experience and a state they are unwilling to leave. They deeply cherish the beauty or comfort this 'dream' brings to them, as well as expressing attachment to it.