Being called (name)-chan?

I did a few searches, but didn't find a satisfactory answer(s), so I want to get a few more opinions and thoughts about this. I know that friends, specifically girls will call close friends using their name and add "chan" to the end. Then children also get their names shortened with "chan" added to the end too.

For guys, I don't hear them using "chan" very often; so my impression is that they don't use it with their friends much. I also speak from my observations because I studied abroad in Japan for half a year awhile ago. One of my friends shortened my name and added "chan" to it; so after she did that, the 2 other guys in our circle of friends started calling me the same nickname. But I didn't mind because I felt we were close friends.

Recently though, I met a Japanese guy a few months ago and I don't know him that well yet. I am also NOT interested in him romantically at all; and we've hung out a couple of times, as a group, to go out to eat or check out events, etc. He's never actually called my name in person; but sometimes when he sends me a text, I noticed he started using my name with "chan"

Personally, I wouldn't consider us close enough friends for him to start using "chan" with me; and I don't necessarily dislike him for using it; but I am just wondering if he's using it because he thinks we're close friends now? Or perhaps he has become romantically interested in me?

I'd really prefer to just be friends, I also don't know if it's because I am 22 and he is 28, so there is a 6 year difference between us. Could it be that because I am younger than him, he thinks it's okay? He never asked if he could call me using -chan and honestly speaking, I don't like to be considered "cute" so part of me feels like I am being be-littled in a way (maybe it's just me).

The best way to know is probably to just ask him directly, but what do you think the reasoning is behind why he's started using "chan"? Any thoughts are appreciated, thanks!

The best way is to just ask him directly.

I realize that, and I will ask him eventually the next time we hang out. But do you happen to have any conjectures? Based on your experiences or observations?

Are you a female? Then I guess he's just one of those "nare-nare-shii" guys. They're kind of like guys who call an Elizabeth Smith "Lizzy" without even asking, when everybody else is calling her Elizabeth or Ms. Smith.

honestly speaking, I don't like to be considered "cute" so part of me feels like I am being be-littled in a way (maybe it's just me).

I would feel the same unless I have feelings for him or something, but I don't think he means any harm or is trying to make it sound like a come-on. He probably just sees you like a younger sister and thinks he's being friendly.

The best way to know is probably to just ask him directly

Not really. The best way, I would say, is to ask one of your other friends from that friendship group. If you're a female, ask a female friend. Or if you really don't like it, you can go ahead and ask him to call you something else rather than to ask the reason.

I ask our Japanese supervior about using -chan on names. He said it can be use anytime and some cases also to boys, but usually use to females.

The best way is to just ask him directly

I also think that it's good to ask the reason behind. It can be awkward when the time you ask that person comes. It's could be that way call someone when texting, as you said you haven't heard him call your name with chat in person.