YOU SAID:

if i didn't know you better i'd think you were lying to me

INTO JAPANESE

私があなたをよく知らなかったなら、あなたは私に嘘をついていたと思う

BACK INTO ENGLISH

If I didn't know you well, you would have lied to me

INTO JAPANESE

私があなたをよく知らなければ、あなたは私に嘘をついたでしょう

BACK INTO ENGLISH

If I didn't know you well, you would have lied to me