YOU SAID:

you act like you've never seen a white person before

INTO JAPANESE

あなたは今まで白人を見たことがないように振る舞います

BACK INTO ENGLISH

You act like you've never seen a white man

INTO JAPANESE

あなたは白人を見たことがないように振る舞います

BACK INTO ENGLISH

Act as if you have never seen a white man

INTO JAPANESE

白人を見たことがないかのように振る舞う

BACK INTO ENGLISH

Act as if you have never seen a white man