happenstance

It was mere happenstance that we both ended up in the same small cafe in Paris.

(Chinese) 纯属偶然，我们最终都去了巴黎那家同样的小咖啡馆。

By a strange happenstance, I found the lost ring while looking for my keys.

(Chinese) 说来也巧，我在找钥匙的时候发现了那枚丢失的戒指。