This is
flash fiction rather than a short story, which is not only a valid form of storytelling but also one of my favourites, so I'm very excited and happy to see someone trying it out here on ScribbleHub!
My main take away is that... the speech comes off as really awkward and I don't know enough about the characters and situation to know if this is intentional or error. Besides that, there are some punctuation errors. Let me give an example:
"What? I have not been smoking for so long. This will go away. Let me open the windows." said Amber.
The lack of contractions suggests a very stiff, formal language. Generally during speech, especially when in conversation with someone close and familiar to us, we don't use this kind of language, and naturally tend toward using contractions. "I
haven't been smoking" rather than "I
have not been smoking", or "
This'll go away" rather than "
This will go away". Using a more formal language isn't wrong, because as I said it can be used to great effect in giving a scene a sense of tension and awkwardness
because it feels so unnatural. But this looks like a scene between two people who are intimately familiar with each other, so it just feels off putting.
Using a more formal writing style by not using contractions is fine in the prose, but when you're writing dialogue it's good to read what you've written out loud to see if it actually sounds like words people would say.
Also, the more common, casual vernacular would be "I have not
had a smoke in so long", I have never heard anyone use what you did.
Punctuation error: You ended the dialogue with a period, but then used a lower case S on "said". It doesn't matter if it's a transition between dialogue and prose, it still functions under the same rules of grammar and punctuation as any other sentence. If you end the sentence with a period, the next sentence needs to begin with proper capitalisation.
As far as where you succeeded: the really fun thing about flash fiction is the way that they can hint at a much larger, but the focus is instead on a single, small moment, or in exploring an emotion or idea without getting bogged down in exposition. The actual concept you have written down here is really well executed, syntax and punctuation errors aside. There's a focus on these two characters and their relationship to each other.
I can immediately pick up on the fact that Amber's smoking is particularly upsetting to Kativa through Kativa's passive aggressive sniffing, showing her disgust and disgruntlement, but also the fact that this is probably something she has brought up many, many times to Amber and she's at a point where she's exasperated with having to mention it and is now just loudly sniffing. I can read a lot about how Amber feels and treats Kativa with how extremely casual and dismissive he is being.
It's not a big deal, I'll just open the window, etc.
This is flash fiction at its best! It walks that fine line between brevity, but really evocative writing. It's snappy and punchy and has this kind of persistent fog of discomfort to it that really makes you feel the lack of stability between the two's relationship/
This isn't to dismiss the advice given by others. If you actually intended this to be a
short story,
not flash fiction, then more setting is going to be required. Unlike flash fiction, a short story needs to be able to stand up and function within its own right. Flash fiction is more flexible because it invites the reader to put everything else aside and just try to embrace the concept of the narrative rather than the details. Since this is part one, if going forward you intend to expand this out from flash fiction into a short story, you do need to give a bit more context.
But whether it's a short story or flash fiction, the function of both forms of storytelling is to be able to tell a single narrative that can be read in just one sitting. Breaking it up into parts for serialised release runs counter to that. Novels work as serialised fiction because they're so lengthy, so breaking them up into chunks through chapter releases works. A short story or a piece of flash fiction is designed to be read and digested in one sitting, and I personally do not feel that trying to serialise it like this is going to benefit audience retention. As other people have said, since this is just a tiny tiny part of a bigger story, it is very very hard to establish any kinds of thoughts or feelings for it until they see the rest of it.
Anyway, this ended up being very long and I apologise, but I was just really excited to see some flash fiction! I think it's a great narrative niche and even if you extend this into a real short story going forward, I would love to see you tackle actual flash fiction in the future because I do think you have a good instinct for it. You successfully created a very definitive mood in what you provided that I found very appealing.