A person who is rude to you but nice to others could be described as selectively courteous or exhibiting differential behavior. They display a contrast in their demeanor and treatment towards different individuals or groups. Here are a few possible descriptions for such a person:
Two-faced: This term implies that the person behaves differently depending on the audience, showing one face to others and another face to you.
Two-sided: Similar to "two-faced," it suggests that the person has two distinct sides to their personality.
Double-standard behavior: This phrase highlights the inconsistency in their behavior, applying different standards to different people.
Fair-weather friend: This term indicates that the person is friendly only when it suits them or when it benefits them.
Jekyll and Hyde personality: Referring to the famous fictional character, it emphasizes the extreme difference in behavior towards you compared to others.
Janus-faced: Taking inspiration from the Roman god Janus, who had two faces looking in opposite directions, it conveys the idea of someone with dual behavior.
Inconsistent demeanor: This phrase describes the lack of consistency in how the person treats people.
It's essential to approach such situations with caution and awareness. Understanding that people may have complex motivations for their behavior can help us navigate these interactions more effectively. If someone is rude to you consistently, it may be worth addressing the issue or reevaluating the relationship if it is negatively impacting you.