YOU SAID:

I'm should defecate and eat cake at the same time.

INTO JAPANESE

私は排便してケーキを同時に食べるべきです。

BACK INTO ENGLISH

I should defecation and eat cake at the same time.

INTO JAPANESE

私は排便し、同時にケーキを食べるべきです。

BACK INTO ENGLISH

I should defecation and eat cake at the same time.