said when someone has done something or when something has happened in a way that you expected and that you do not approve of

"I've forgotten my keys again." "Surprise, surprise!" “我又忘记带钥匙了。”“真是意外啊！”

said when you are telling someone about a situation in which something unexpected and pleasant has happened

I asked him if he wanted to come to dinner, and surprise, surprise, he said yes! 我问他想不想来吃晚饭，太让人惊喜了，他竟然答应了！