Americans generally use the structure spring (something) on (someone).

美国人一般使用 spring (something) on (someone) 这个结构。

So, if I spring something on you, I tell you with no warning.

所以，如果我突然对你说了什么，那么我就是毫无预兆地告诉你。

While you're in a good mood, I thought I'd spring something on you. My parents are coming to town.

既然你心情好，我想我要宣布件事。我父母要到镇上来了。

I thought I'd spring something on you.

我来给你降降温。