I'm confused about the story of Dev's feast. Who were the three uninvited people who showed up, and why was Dev so upset afterwards?

The three seemingly uninvited guests at Dev's Udyapan ceremony were actually Sai Baba in the form of a Sanyasi, along with two other individuals he brought with him. According to the account in Chapter 40, Baba had promised Dev he would attend with two others. Dev became upset and felt deceived because he was expecting Baba to appear in his familiar form and failed to recognize him in the Sanyasi's guise. His disappointment stemmed from this misunderstanding, leading him to write a letter to Jog complaining that Baba's word had failed and he had received no spiritual experience, not realizing he had personally served the very person he was waiting for.