I'm in a team of Trainee/Associate software Engineers in their early 20's. I'm over-experienced to my role, so I handle a major part of the project. My tech lead / Seniors and Heads are much closer to me and value my inputs. The company let me re-engineer the whole process and lead the project by myself.
Since things are going quickly, a few colleagues have become jealous. I have observed an inexperienced and introverted colleague who is older than me demonstrating that and trying to associate bad nicknames and stereotypes with me behind my back. Being my next table, this distracts me from work.
I have told this person various times on various occasions in various tones that I don't want this and this is unethical. I have said this even in front of my tech lead, but this person is desperate. He gives a fake positive answer and continues the behaviour. How can I approach this colleague to be professional and follow work ethics?
EDIT: I don't want my boss to know about this because he promised to promote me in another 4 months. If I escalate or let escalate this "childish" behavior of the colleague, it will make me look immature. After promotion, this problem will be gone.