YOU SAID:

the president ate Doritos whilst playing on a Mariokart DS on a DS

INTO JAPANESE

大統領はDSでマリオカートDSをプレイしながらドリトスを食べた

BACK INTO ENGLISH

The president ate Doritos while playing Mario Kart DS on his DS

INTO JAPANESE

大統領はDSでマリオカートDSをプレイしながらドリトスを食べた

BACK INTO ENGLISH

The president ate Doritos while playing Mario Kart DS on his DS