YOU SAID:
what's your cup size?
INTO JAPANESE
あなたのカップサイズは何ですか?
BACK INTO ENGLISH
What is your cup size?
INTO JAPANESE
あなたのカップのサイズは何ですか?
BACK INTO ENGLISH
What is the size of your cup?
INTO JAPANESE
あなたのカップのサイズは?
BACK INTO ENGLISH
What is the size of your cup?
That didn't even make that much sense in English.