YOU SAID:
what the most embarrassing thing that's ever happened to you.
INTO JAPANESE
これがあなたにとって今までで最も恥ずかしいことです。
BACK INTO ENGLISH
This is the most embarrassing thing you have ever done.
INTO JAPANESE
これはあなたが今までで最も恥ずかしいことです。
BACK INTO ENGLISH
This is the most embarrassing thing you have ever done.
That didn't even make that much sense in English.