The phrase "up one's own ass" is a colloquial expression used to describe someone who is overly self-absorbed or narcissistic. Its use can be offensive or vulgar in nature. When looking for synonyms to express a similar sentiment without the crassness, some alternatives include "self-important," "egotistical," "self-centered," "conceited," or "arrogant." These words can still convey the meaning of someone who is overly focused on themselves, but in a more professional and socially acceptable manner. It is important to choose words wisely when communicating to avoid offending others or appearing unprofessional.