What's the meaning of the phrase 冗談は顔だけにして下さいよ in English? According to Google translator, it means "Joke should only be in your face" which makes no sense to me.
It's a classic Japanese joke, which is also very derogatory.
Google Translate did a good job in this case — it obviously understands that this phrase is more or less idiomatic. This sentence actually means "Please make your face the only thing that's joking here" or more descriptively, "No more joke please, your face is already funny enough."
According to this article, this phrase originated from the Japanese version of Diff'rent Strokes. Someone translated the catchphrase of the drama, "What'chu talkin' 'bout, Willis?", to 冗談は顔だけにしろ for some reason, and this phrase gained popularity in Japan.
This phrase (and variants) are still sometimes used by Japanese comedians.
Google translator gave me "joke should only be in your face"
That makes perfect sense. Good job, Google translator!
The jab 冗談は顔だけにして ... seems pretty old, maybe from the 1960s or 1970s ?
http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1018265750 -- もう昔のことで名前も思い出せませんが、漫才コンビがいて、顔が気の毒なボケ役のぼけに対して、相方が、｢冗談は顔だけにしてくれ｣と言ったのが、始まりです。（やすし・きよし時代よりも前のことです。）