So there's this girl (F22) that I (M20) met back in early 2016 during my second semester of my undergraduate program. We had great chemistry and have always enjoyed each other's company and there was never a dull moment between us. I wanted to pursue things a bit further but she she made it clear that she was not interested in a relationship with me so we remained as good friends.

Here's where things get a bit more complicated. Even though we were never in a relationship, we went out with each other a lot (lunches, dinners, you get the idea) there were lots of hugs and cuddles (no kisses or anything beyond that), some occasional hand holding, calling each other nicknames, said "I love you" to each other: things you would normally expect out of a platonic friendship, right? She even went as far as cancelling a date just for us to have dinner together, which was nice, I thought.

About 1.5 years (Early 2017) into our friendship, she did something that really made me angry and I broke off contact with her as a result (it wasn't the first time she made me angry, but we eventually patched things up after a short while with lots of "dates" and hugs, but this one was the longest). Things were messy, I was in a slight state of depression for a while (she was as well, she made a couple of Instagram posts indirectly referring to me about losing me and how she felt). Do take note that this is the only time I've seen her making a post about losing someone. She's never made a post about her past ex-boyfriends.

Fast forward to mid 2018, I'm (M23) in an actual relationship with another girl for about a year now. However, the girl (F25) and I started getting into contact with each other again, not for personal purposes but for business. She was doing an internship that I was applying for and wanted my CV and available time for an interview. I'm pretty sure that she was doing this on purpose just so she has a chance to talk to me again but whatever.

In between mid-2018 and late 2018, I came to the realization that what happened in the past was easily avoidable by me, as I had to play a role in this as well. So I let my anger go upon further self-reflection.

It was only after a graduation dinner (late 2018) that we started getting into talking to each other again as I dropped her off at her place after the dinner. We made amends as we said goodbye, and that's when things started kicking off again. My girlfriend was not happy about this as she felt that there was a hidden intention behind it but I doubt it as the girl knows I'm in a relationship.

We still see each other from time to time but there's no more of the cuddling, nicknames or intimacy that we once had. I still feel the slight tension and chemistry in the air but we both never took it one step further. it would be wrong to do so and she's also casually seeing someone else for the time being. However we do keep very active contact (messaging and calling) with one another via WhatsApp & Instagram on how our lives are.

It'd be safe to consider now that we're best friends again.

I really love her as a friend (probably as a partner if I wasn't committed) and I'm really happy that we're talking again and all but the question that I have lingering in my mind for a while is this:

Usually from past experience, after something drastic has happened, contact would be cut off or minimal (as I had with all my exes). Yet for some reason, we keep coming back to each other even after such a drastic experience, given time. And yet, despite having opportunities in the past, we wouldn't be in a relationship since she made her stance (which I totally respected).

I'm an atheist, but somehow I always feel that fate has bound us together. It's either a blessing or a curse given that we can't really get rid of each other.

My main question is what drives a woman to want to continuously stay in close friendship with a man who she clearly has no relationship interest with despite having multiple fights with him in the past that would almost permanently end communications between friends (or couples) in similar situations?

This question is bothering me and I'd really like an answer, if possible.

The story is a lot longer (and more complicated) than it is but I wanted to keep it focused. Ask away if you want to know more about my story.

tl;dr met a girl friend during junior year in university, had great chemistry, fought a couple of times and made up for it. However, broke off contact with her for about 1.5 years. Fast forward to now, we're talking to each other again. Case like this would simply just end communications with one another permanently. Why is this case different?