Unenthusiastic Surprise Party Response

We all know and Любовь our too-cool-for-you characters. They're Друзья with Ты and Любовь you, even though they find it rather hard to Показать it.
So let's say this person has a birthday coming up and his Друзья decide to throw him a surprise party. What do Ты think would be his reaction once they yell SURPRISE!?

I know that he's both happy as well as annoyed that his noisy Друзья did this without his consent. And he won't be rude to them, cos that would be..well, rude.

Ты can give a simple explanation as an answer, или Ты can write a sample scene. Thanks for your help in advance!