I have been working in an international company here in the US since a year. I am a senior scientist and expert in the field and work in the similar capacity. I have this south Indian co-worker, who acts very rude to me. I am in general easy going, simple person that works hard and in volume. This guy is junior to me and has been working since past almost three years.

This guy talks well with others but ignores me and I have a feeling he does have some passive aggression towards me. He sucks up to the khaires and especially seniors. I have a khaireni colleague whom I know from my grad school (we were in the same research group). She is junior to me and works with the same designation as this Indian guy. He kisses her ass and acts as the nicest guy in the world but when it comes to me he acts like he is some kind of big-shot. He never admits he does not know something. He "knows" everything.

Every time I see him, it makes me feel cringy. I have a feeling he backstabs behind me and bitches about me with other junior staffs too. Because of his attitude, my work-life balance has been little affected. I feel like not wanting to go to work as it gives me too much negativity. My boss and other seniors like me. They have implemented changes I initiated. He is also liked. I have some feeling that he is insecure with me. I don't know, I might be wrong.

Do you guys have any Indian co-worker that acts that way? I've read a lot about such attitude (Kiss up, kick down) in Indian at workplaces. Please share yours and suggest me what I should do. I really am starting to hate this guy.