Of Ethics and Flirting? I Need Opinions

The course of true love never did run smooth...

Frankly, I am not thinking about love, just being fond of someone, being endeared by someone, simply enjoying their sense of humor, for god's sake, and bantering.
I live for banter, it completes me.
A person can go through their entire day only reading from the list of pre-approved replies, and I guarantee you that they are dying a little with each stale response.

I moved to a small town in the country last year, and only last month was I able to find a job. I now work at the local grocery store, and because my first year in town was spent writing crappy articles out of my bedroom, no one really knows me and visa versa.
Being the new face in a small community that most people in the area have never even heard of, seems to attract a bit of attention. I've had people watch me closely, been grilled for my information (where I came from, how I found the town if I live in town, my name, age, etc) Sometimes I find it all very aggravating, and like it belongs in a Stephen King novel. But mostly, I am simply bored of it.

Which leads me to the love/like thing.

One of the regular customers is a young guy who (I believe) works across the street from the store. When I first started the job, everyone seemed to either be bombarding me with questions or watching me like a hawk to see if I was going to fuck up their transactions. He joked with me a bit and helped put me at ease that first week. Especially my first solo.
After I finally got a set schedule, I wound up working a lot more nights, which, evidently, are when he comes in most. So we've struck up this kind of sarcastic one-upmanship thing.
Technically, I understand that what he is doing is flirting, and by throwing it back at him, I understand that I am (good god) "flirting" back.

The thing is this. I do actually think this guy is funny, he's endearing in a Jesse Pinkman kind of way, and yeah, I frequently feel like Walt White.
That all seems simple though, right? He flirts with me, I flirt with him (good god), he seems to like me at least a little, and I can admit to being fond of him. So fucking simple.

Except it's not.

I don't want to date anyone, mostly because I don't want to explain myself to them. I'm asexual, which is frequently a source of confusion and a major dealbreaker. I get that, if someone wanted to have sex with me, THAT would be a major dealbreaker.
Furthermore, my whole gender identity is a mess, and I feel like being in a relationship would only serve to exacerbate the issue. I don't believe that it's particularly safe to be who I am in the majority of America. I don't want those problems for me, and I especially don't want those problems for my family.

My mom believes that I have no idea that this guy is flirting when he sticks around to banter with me, but I do. She doesn't believe that I understand that when I banter back, that I know that it's technically flirting, too.
I prefer to keep it that way, but it also forces the uncomfortable reality of my position in the world. Is it even right for me to tease back, even if I do actually like the person, simply because I can't really have intentions of being anything more than friends that banter?
If I like someone, the chances of them liking me, in the same way, are very small.

I used to think that I wanted to be alone forever, never letting anyone too close, never creating a bond because all I ever knew of bonds was that they broke, and were so often lies from the beginning. It's a sad education.
But what if I could have something real? What if I didn't have to be alone? Is that even possible for someone like me? I don't know. I may never know.

I do know that I never want to lead someone on. Never want to mess with someone, or make them feel played. Asexual ethics are an absolute pain in the ass.