But you'd better be damn careful you're not talking to some denouncer.
但你千万要小心他不是内奸。
英语百科
Denunciation
(重定向自Denouncer)
Denunciation (from Latin denuntiare, to denounce) is an open public accusation or reporting a person or a group of persons to public authorities, often done anonymously for low political or personal motives, on which the informant has a personal interest or hopes to gain personal benefits.