thanks for nothing

Theodore Boone kid lawyerを読んでいると、こんな場面がありました。
“Miss Garman, is Theo Boone in class?” It was the shrieking voice of Miss Gloria, the school’s longtime secretary.
“He is,” Miss Garman responded.
“Please send him down. He needs to check out.”
Theo grabbed his things, stuffed them into his backpack, and as he was hustling toward the door Miss Garman said, “If we have a quiz, Theo, you can make it up on Monday.”
Well, thanks for nothing, Theo thought, but instead he said, “Can’t wait.”
英語圏の人は日本人より思った事をストレートに言うと聞いていますが、やはり何でも思ったことを口に出すようではない様です。