YOU SAID:

if you were mine you wouldn't be able to sit down for a week

INTO JAPANESE

あなたが私のものだったら、一週間座れないだろう

BACK INTO ENGLISH

If you are mine you will not be able to sit for a week

INTO JAPANESE

あなたが私のものであるなら、あなたは一週間座ることができないでしょう

BACK INTO ENGLISH

If you are mine you will not be able to sit for a week