YOU SAID:

someone pooped ther pants...

INTO JAPANESE

誰かがパンツをうんちした。

BACK INTO ENGLISH

Someone pooped on his pants.

INTO JAPANESE

誰かが彼のズボンにうんちをした。

BACK INTO ENGLISH

Someone pooed on his pants.

INTO JAPANESE

誰かが彼のズボンにうんちをした。

BACK INTO ENGLISH

Someone pooed on his pants.