Bilingual Navigation

I am working on a pro-bono project. We are designing a website for a bilingual parent workshop (80% Spanish Speakers and 20% English Speakers). Funders for the organization are English speakers. That is why we must include both languages. We have limited resources with development. Design is being asked to creative with the tasks.

I was asked to include both languages on the navigation (Spanish and English).

The navigation would look something like this: Home/Inicio About/Sobre Nosotros Gallery/Galleria

Are there any UX rules that goes against what I am being asked to do? I've never seen a navigation like this before.