YOU SAID:

back stabbing friends are not very good ones

INTO JAPANESE

背中を刺す友人は非常に良いものではありません

BACK INTO ENGLISH

A friend stabbing the back is not very good

INTO JAPANESE

背中を刺す友人はあまり良くありません

BACK INTO ENGLISH

A friend stabbing his back is not very good

INTO JAPANESE

彼の背中を刺す友人はあまり良くありません

BACK INTO ENGLISH

A friend stabbing his back is not very good