The statement "it's irrelevant what you are saying now" coupled with a yawn can be considered rude and disrespectful. It shows a lack of interest and consideration for the other person's thoughts or feelings. Yawning while someone is speaking can be interpreted as a sign of boredom or disengagement, which can be hurtful and discouraging for the person trying to communicate.
While this behavior might not necessarily indicate narcissism directly, it does display a lack of empathy and social awareness. Narcissism involves a pattern of self-centeredness, an inflated sense of self-importance, and a lack of empathy for others, among other traits. Someone who consistently displays disrespectful behavior and disregards the feelings of others may have narcissistic tendencies, but it's essential not to jump to conclusions based on a single incident.
It's crucial to communicate openly about such behavior if it occurs frequently, as it can lead to strained relationships and communication breakdowns. Addressing the issue with the person in a calm and constructive manner can help create a more respectful and understanding dynamic in the future. However, it's also essential to consider context and possible underlying reasons for their behavior, such as fatigue or stress, before making judgments about their character.