YOU SAID:

if flies fly behind flies then do flies fly after flies

INTO JAPANESE

ハエがハエの後ろを飛ぶ場合、ハエはハエの後に飛ぶ

BACK INTO ENGLISH

If a fly flies behind a fly, the fly flies after the fly

INTO JAPANESE

ハエがハエの後ろに飛ぶ場合、ハエはハエの後に飛ぶ

BACK INTO ENGLISH

If a fly flies behind a fly, the fly flies after a fly

INTO JAPANESE

ハエがハエの後ろに飛ぶ場合、ハエはハエの後に飛ぶ

BACK INTO ENGLISH

If a fly flies behind a fly, the fly flies after a fly