“I’m not interested. Please leave me alone.”

Most of what I’m seeing here sounds too confrontational or passive aggressive to me. What I would do personally is wait until he asks you if everything is okay again and then say something like this:

“Yeah, all good here. So you know, I’m not quiet because something is wrong in my life or between us, I’m just very introverted and my natural state of being is not to open up”

Most people tend to assume other people’s internal state is works similarly to their own, unless it’s an aspect where they know they are far removed from the norm, so for an extrovert, they equate you being quiet to what would cause them to be quiet. Without telling him the reason you act differently, he will continue to assume this.

By wording it as an FYI, you give the opportunity for him to understand the difference and change his behavior without telling him he has been doing something wrong, because best as he knows he hasn’t been, and so you hopefully prevent him from getting defensive.

If he continues, then maybe you can go to a more confrontational approach. That’s how I would handle, at least.

I am also a woman and I’m guessing you are not from your username, so ymmv with communication like this.

This website completely changed the way I thought about this stuff and I found it super helpful.

The line to walk, generally speaking, is, “When you do [specific behavior], it makes me feel [specific emotion].” So for example, “When you ask me if everything’s ok, it makes me feel pressured/put on the spot.”

Keeping it about your own feelings makes it less confrontational while still bringing attention to the problem - you don’t wanna get drawn into a whole debate about whether there’s anything wrong with asking if someone’s ok, but you want him to understand how you feel and (hopefully) take that into account in the future. If he does get defensive, repeat the message once to make it clear you’re standing your ground, but then drop it and move on. A lot of times it’s just a matter of the other person not realizing how it affects you.

Having said that, speaking as someone who’s very much had the same mentality in the past, there are a lot of advantages to having friends in the workplace. Something to understand about this approach is that it’s actually good for building relationships because it allows you to confront the behaviors that bother you while openly communicating your feelings, and people may even respect you more for standing up for yourself. Just remember to walk a middle ground, you don’t want to veer into aggression or passivity.

“Everything is good, thanks. Staying busy with work…” and then either get back to work or stare at them until it gets awkward. Its possible they have trouble with social cues and you seem friendly or nice or whatever, people are weird and being a new employee is stressful so trying to latch onto someone who comes across well can be a thing that happens. I try to redirect people like this to the topic of work and answer any personal question with something boring. What did you do this weekend? Laundry. If they have any self awareness they will eventually only talk to you about work. Stay professional and don’t be rude while making it clear you are at work to do work and have no interest in their personal life or sharing any details of yours.