说你是渣你信吗
[shuō nĭ shì zhā nĭ xìn ma]
'Are you going to believe me if I say you're scum?' This is a humorous way to express doubts or frustrations regarding how others perceive oneself, or conversely how they feel towards others. There’s irony involved in questioning one's credibility after making such a statement. However, it depends on tone, culture, and context as to the intended effect.