YOU SAID:

I've decided to go and eat lunch in the bathroom because why not

INTO JAPANESE

トイレに行ってランチを食べることにしたの

BACK INTO ENGLISH

I went to the toilet and decided to eat lunch.

INTO JAPANESE

私はトイレに行き、昼食を食べることにしました。

BACK INTO ENGLISH

I went to the toilet and decided to eat lunch.