YOU SAID:

You need to slap that stupid face.

INTO JAPANESE

馬鹿な顔を叩くんだ

BACK INTO ENGLISH

You're gonna slap me in the face.

INTO JAPANESE

俺の顔を叩くぞ

BACK INTO ENGLISH

I'll slap you in the face.

INTO JAPANESE

顔を叩いてやる

BACK INTO ENGLISH

I'll slap you in the face.