YOU SAID:

i saw a play once where they did that

INTO JAPANESE

一度、彼らはそれをしたプレイを見た

BACK INTO ENGLISH

Once they saw it play

INTO JAPANESE

彼らはそれを再生を見た後

BACK INTO ENGLISH

After they saw it play

INTO JAPANESE

彼らはそれを再生を見た後

BACK INTO ENGLISH

After they saw it play