YOU SAID:

oh my god no! why would you do that

INTO JAPANESE

なんてこった！なぜそんなことをするんだ？

BACK INTO ENGLISH

Oh, my God! Why would you do that?

INTO JAPANESE

なんでそんなことを？

BACK INTO ENGLISH

Why did you do that?

INTO JAPANESE

なぜそうしたんですか。

BACK INTO ENGLISH

What did you do that for?

INTO JAPANESE

なぜそうしたんですか。

BACK INTO ENGLISH

What did you do that for?