My Associate is a C*nt

I’ve been struggling with an associate I’m staffed with on a few deals. Everyone else I work with is extremely supportive and helpful but this one dude is just extremely unpleasant and behaves like a total cunt. He is constantly giving me a hard time, does not give any helpful feedback and lately has been actively making me feel like I’m not part of the team. In many instances he has explicitly told me not to join client calls or in-person meeting (without me asking) even when I’ve made it clear that I’d like to observe/learn and take notes.

I’ve been trying to swallow all this nonsense and continue being kind without any questions asked but to be honest much of his bull shit feels very personal and targeted which I think largely has to do with him projecting because of his own insecurities. Normally I am very comfortable confronting people and level setting but this guy is a complete toss up in terms of his behavior and I feel that confronting him would only perpetuate the issue further. I’m not one to fackin narc on someone else to a more senior person but I’m feeling unsure on how to resolve this issue without doing so. All this has been affecting my productivity and has made me feel a little unsure of myself.

Any advice or suggestions here would be very much appreciated. Cheers