YOU SAID:
You didn't truly pee in his Cheerios, did you?
INTO JAPANESE
あなたは彼の Cheerios で本当におしっこをしませんでしたね?
BACK INTO ENGLISH
You really didn't pee in his Cheerios, did you?
INTO JAPANESE
あなたは本当に彼の Cheerios でおしっこをしませんでしたね?
BACK INTO ENGLISH
You really didn't pee in his Cheerios, did you?
That didn't even make that much sense in English.