Speak of the devil 英文諺語
Speak of the devil (and he shall appear) 說曹操曹操就到
Also: Talk of the devil (and he is sure to appear)
Something you say when the person you were talking about appears unexpectedly; talk about a certain person, and that person appears (used when someone appears whom you have just been talking about).
This phrase, in its current usage, is a lighthearted way of referring to someone who has unexpectedly come in when being talked about, however, prior to the 20th century, it wasn’t a lighthearted one. The full form of this phrase is “Speak of the Devil and he will appear”, and was meant to warn people not to talk about the Devil. It was widely known and used by the mid 1600s. The phrase originated in England, where it was, and still is, more often given as ‘talk of the Devil’.
Frank: “I haven’t seen James for weeks.”
Kate: “Look, here comes Bob right now.”
Frank: “Well, talk of the devil. Hi, there. We were just talking about you. speak of the devil and in he walks.”