YOU SAID:

My bestie and your bestie sit down by the fire

INTO JAPANESE

私の親友とあなたの親友は火のそばに座ります

BACK INTO ENGLISH

my best friend and your best friend sit by the fire

INTO JAPANESE

私の親友とあなたの親友は火のそばに座っています

BACK INTO ENGLISH

my best friend and your best friend are sitting by the fire

INTO JAPANESE

私の親友とあなたの親友は火のそばに座っています

BACK INTO ENGLISH

my best friend and your best friend are sitting by the fire