Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: Context: I'm a Level 1 tech working in a IT Helpdesk dedicated to our company as well as a few external clients; I'm fairly new as I've only been working there for about 5 months.

One of my colleagues, who shall be known as Steve for the point of censoring, has been working for about 2 months, doing exactly the same job as mine and sitting right next to me in an open office. We have the same manager, who's taking care of about half of the helpdesk's techs. I like him, I really do, but he's having a nasty habit, and I want him to at least be warned of the said nasty habit rather than getting fired.

Anyway, I've noticed about two weeks ago that sometimes (about once per two days), he's having a hard time dealing with our users (which I don't blame him for), he mutes his phone and says rude comments such as "Shut up", "I don't care" or just a plain old "Fuck you".

Now, since I do exactly the same job as his, I get the frustration I might have. I gave him my own trick when this happens (albeit it's much more rarely since I'm fairly patient): to use my hands and do a soundless strangling gesture; I also advised him about how another of our techs has a stress ball for this exact reason.

Anyway, I also warned him that our calls are recorded, and that he could be in huge trouble if he would either forget to mute himself or if someone from our QA program were to get ahold of a phone call where he'd be doing this; huge trouble as in one from QA, or even worse, external clients/employees could report this to higher management than our manager.

Speaking of our manager, he's pretty understanding and got our backs; I'm almost certain that he'd let it go this time since he's fairly forgiving and due to the fact that it's pretty hard to get fired here.

Obviously, I'd ideally not want to go through our manager, but after telling him more than 5 times, I believe he needs a firmer warning before it gets in higher management.

So, redditors, WIBTA if, despite my best efforts, I were to report my coworker's occasionnal rude behavior with the goal in mind that he stops before he gets fired for it?

TL;DR: Coworker's rude towards our clients, and his job is half customer service; I want him to be warned rather than fired, and my own warnings wouldn't go through.

being to talk to my supervisor about a colleague's bad behavior after talking to him about it