Unenthusiastic Surprise Party Response

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

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

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