No, they sound different enough for a native speaker to tell the difference pretty easily. I've recorded an example. A native speaker knows which word is meant, in the places I have indicated with question marks, even though either word could make sense. https://vocaroo.com/i/s1LqKcqQ6YCC "Princess. Princes. Princess. Princes. Princess. Princes. Hans Christian Andersen wrote a famous story about "The ???? and the Pea." Shakespeare's play, Richard III, includes the story of the "???? in the Tower." Hans Christian Andersen wrote a famous story about "The ???? and the Pea." Shakespeare's play, Richard III, includes the story of the "???? in the Tower."

I'm afraid they are not pronounced the same. It's subtle, but a native speaker would never confuse them (unless perhaps there's a lot of noise on the call). princes /ˈpɹɪnsəz/ princess /ˈpɹɪnˌsɛs/

They sound different. "Princes" sounds like [prints] with the addition of "iz" sound at the end. The 'i' of the 'iz' sound is very weak, and sometimes might be undetectable, so it could sound like [prints'z]. For princess [print-sess], there is an 'ess' sound at the end, and the last syllable is strong, sometimes even having stress for the word.