I appreciate that you have written the definitions of love and infatuation because it is essential in the story because (I assume) this will be the theme of the story. Since it's about Minah's decision whether she'd pick Siwon or Jimin. But, this can be done at the end of the description or in your foreword. I'm saying this because when your story is presented in aff (say, you have just posted a new chapter and someone was browsing for latest updated chapters) what they're going to find instead is the definition instead of the brief summary of the story. I have also learned from several sites and readers themselves that reading definitions about what the chapters mean turn them off from the story. The effort is there, but it sometimes seem redundant considering that the two words being defined are not new to us.

Then, for your actual description, I like how you described their characteristics. That's a good way of making a summary because it helps us know what kind of person our idols are portraying in the story. There's also the constant use of how the two characters thrive to be simple and/or simple beings. I have to admit that I have to read it several times to finally understand what you meant. This might be due to the fact that I'm doing this at three in the morning instead of sleeping.

Between Love and Infatuation tackles a sensitive issue that's prevalent in the society. No matter how rampant adultery is, marriage should still be taken seriously. I do not know how things would turn out in the future because as of now, the story's still on its third chapter, but I'm praying and hoping that the author won't mess up anything about this. I'm not shading any other stories here (since some got popular) but adultery should never be romanticized. No one wants to know that the person they devoted themselves have been seeing someone else. That's tragic.

Big props for the author for putting new quotes every chapter. I find it poetic for no apparent reason. Then, your lay-outs weren't freaky, and I also adore your graphics. (I'm left here wondering if you really asked the same graphic shop to make you one each chapter). 

I'd put it into consideration when you said that you're still not confident in writing in English because it clearly shows. I'd admit I'm not good on the language even though I have been speaking it from the day I was born, so I know that it's really hard. There were some grammar efforts here and there and some typographical errors. I know that you have finally found a beta-reader and I'm happy for you, so I'm just going to list the major mistakes I found in great hopes that you and your beta-reader can fix it. Take this as a small guide. 

*You tend to use short paragraphs. By means of short, I mean one-sentence-only short. There were some exceptions on the rule of paragraphing but in the first part of your first chapter, almost all paragraphs contained only one chapter, when instead, it could be joined into one paragraph. This changed in Chapter 2 though. The paragraphs were of decent size and it wasn't compelling, but this practice came back again at Chapter 3.
*You constantly use 'didn't' instead of other contractions such as couldn't, wouldn't or doesn't. For example, instead of "She didn't know what the sigh was for...", it should be "She doesn't know what the sigh was for..." Did shall be used for plural nouns while do/does shall be used for singular ones.
*You don't describe the scene most of the time. There's this rule about writing where you have to use your five senses when writing a scene. This part is tricky because some tend to overdo it and it can't be learned in just a snap of fingers. Between Love and Infatuation felt like I'm watching a k-drama instead of reading a fanfiction (or a novel because I see fanfics as novels) because the scenes pan in and out quickly. It would be better if you put in descriptive words about how a character looks like, or how they act or even what their environment looks like. Play with the words. Writing is an art form and become a writer (I sound like an enthusiast of a cult, lmao). Don't stress yourself about this that much though. There's a lot of writing sites in tumblr that can help you regarding this.

I also wanted to include the fact that Jimin is a security guard in this fanfic. I saw Jungkook as a policeman due to their Dope promotions but now that I read your fanfic, I can't erase the image of Jimin in a white uniform. Oh lala. And it's a crackship! Bless this fanfiction side where new ships are born! 

Also, is it only me who found Minah's thoughts about hating people who find people who play with people's feeling as the worst kind of people to be ironic? I mean, I'm pretty sure that's what's going to happen in the ensuing chapters. I'm still figuring out whether it'll be Siwon (and his Secretary) or Minah herself that'll do the diry deed and where Jimin will be at the end.

(Also I'm predicting Yoona to like Jimin. Come for more angst)

Note: I kinda feel awkward doing this review because I also work in your shop but a job is a job. I'd like to apologize if in this review, the negatives outweigh the positives. There's still a room to grow. Never feel discouraged about what I said and use it as a stepping stone for you.

Thank you for requesting, and I hope you'd come again.