Feeling uncomfortable that I haven't come out to particular friends

This is maybe a bit of an odd one...

I'm in the process of figuring out my sexuality (current best description: not as straight as I always assumed I was). I'm very lucky that I have a lot of LGBT friends - I started playing roller derby last year, and over half my league are gay - it has been eye opening.

I spent a while working out a lot of stuff in my head before I felt able to talk to anyone about it. The first person I 'came out' (I use the term loosely, as I'm still not clear how to define myself, so it's more 'discussed it with' I guess) to is my best friend from roller derby - she is the one person who I feel like I can genuinely talk about anything with, and is also bisexual, so I knew she'd be understanding (and helpful!) on that front.

I've since discussed it with 3 or 4 other friends - a couple also from derby, and another close, non-derby friend. With all of these, it has just sort of come up in conversation - with one we were discussing the proportion of our team who identify as non-straight, and she said she felt she was straight-ish, so it was quite natural for me to talk about what I'd been feeling.

But there is one key group of friends who I haven’t yet discussed it with, and I’m feeling increasingly awkward about the fact that I haven’t. They are also from derby - there are a few of them who live together, who are all lesbians, and all absolutely wonderful. I split up with my boyfriend a few months ago and they were the most incredible support to me - they were the people who provided a shoulder for me to cry on, and when I’ve been feeling desperately lonely and just need to see people and have a hug, they have been the ones I’ve called, and they have always been there for me. In short, amazing, incredible friends, and I am very lucky to have them.

I’m not sure why I haven’t told them yet. Partly because it hasn’t come up in conversation naturally like it has with some of the others, and I really don’t want to make a big *thing* of it. I kinda want to just come out in a casual comment, if that makes sense (this being the very LGBT friendly derby world, I feel super comfortable with that - it really is not a big deal with this group of people). But I think maybe there’s something else there. Like maybe people who are actually real lesbians will think that I’m saying that just because I started playing derby and loads of my friends are gay and it’s the ‘cool’ thing (totally not the case). It’s wasn’t a conscious thing, but I’ve realised that all the people I’ve discussed it with so far identify as somewhat bisexual (so, a similar situation to me, given I recently ended a long term relationship with a man), rather than completely gay. There are also two couples in this group I haven’t told, which I think makes it harder, as I often seem them together, rather than one on one.

It wouldn’t be an issue, but I’m really aware that I’ve started discussing this with more people, and don’t really have an issue with doing so. I don’t want these very close friends, who have been so wonderful at looking after me over the last few months, to be the last to know. There have been some conversations I’ve had with other people where I’ve actually had to stop myself mentioning it, for this reason. I feel like they might be hurt that I run to them every time I need someone to cry on, but yet didn’t feel like I could discuss this with them (even though, given that they’re all gay, they would likely be nothing but supportive, and also probably have a lot of useful advice for me). I really want to be able to talk to them about it, but it just doesn’t seem to come up. I’m pretty sure most people I play derby with assume I’m totally straight, and so no one’s ever actually asked me, which would be an easy way to deal with it. Am I massively overthinking this, and what their reaction might be? Does any of this make any kind of sense? Any advice for how to deal with it? The fact that I haven't told them yet is currently stressing me out more than the fact that I am probably not straight after all.