YOU SAID:

I have never seen two pretty best friends always one of them has to be ugly

INTO JAPANESE

私は2人のかなり親友を見たことがありません常にそのうちの1人は醜い必要があります

BACK INTO ENGLISH

I've never seen two pretty best friends and always one of them should be ugly

INTO JAPANESE

私は2人のかなり親友を見たことがなく、常にそのうちの1人は醜いはずです

BACK INTO ENGLISH

I haven't seen two pretty best friends and one of them should always be ugly

INTO JAPANESE

私は2人のかなり親友を見たことがなく、そのうちの1人はいつも醜いはずです

BACK INTO ENGLISH

I haven't seen two pretty best friends and one of them should always be ugly