YOU SAID:

I smell farts but I'm home alone

INTO JAPANESE

おならの匂いがするけど、一人で帰ってきた。

BACK INTO ENGLISH

It smells like fat, but I came home alone.

INTO JAPANESE

脂肪臭いが一人で帰ってきた。

BACK INTO ENGLISH

The smell of fat came back alone.

INTO JAPANESE

脂肪の匂いがひとりで戻ってきた。

BACK INTO ENGLISH

The smell of fat came back on its own.

INTO JAPANESE

脂肪の匂いが勝手に戻ってきた。

BACK INTO ENGLISH

The smell of fat came back on its own.