This is quite a trivial issue in the scheme of things, but it's been playing on my mind and I genuinely can't tell if IBU here, so I thought I'd put to Mumsnet to decide.
Recently, a close friend (A) and I asked another friend, B, to help us learn a hobby that B is really good at. As we had discussed it first at a party, a couple of other people we know also asked to join in and we formed a chat group to start planning sessions. The whole thing was fairly informal and flexible as B wasn't charging for helping us and we said whoever was free could join, if not no problem.
We had our first session a few weeks ago and only A and I attended, along with our friend/teacher, B. The next week we confirmed it was the same place and same time but the week after A was unable to attend and I attended with B and another person from the group. So far, that was 3 sessions in total and although it was the same time and day each time, I always made sure to check B was still free to help the day before.
Mid-last week, B said she wouldn't be free the next 2 weekends but that we should feel free to practice without her. A and I had previously spoken about how important it would be to practice regularly and be consistent - we'd both aimed to practice by ourselves sometime too if we were able to. A responded to B's message on the group saying that she was looking forward to practice on Saturday.
I didn't think anything further of A's comment and we didn't speak separately about meeting on Saturday. On Saturday morning I woke up to calls and messages from A, asking where I am. She had messaged through on the group after midnight on the Friday (technically the Saturday!) asking if we could meet at 930am instead of 9am (the time we had met thrice before). I didn't respond to that because I was already asleep and didn't see her other calls and messages because I'd only woken up around 10am.
It turns out that A was really worried and messaged my husband and others saying I hadn't 'shown up' and asking where I was. She had assumed that her message about practice on Saturday had meant we were still going ahead and even though she hadn't heard anything to confirm from me, still went ahead and waited for me at the hobby centre.
In my mind, just because we'd done the same place and time 3 weeks running didn't mean we had a standing arrangement, as demonstrated by A herself not coming the previous week. She thought her comment about looking forward to practice on Saturday was clear enough but to me, that comment didn't mean much without follow-up, and the follow-up came too late for me to see it! Also, no one else from the group attended either, which suggests that it was less a 'standing arrangement' and more of an opt-in. A also pointed to the fact that we'd said we need to be consistent and regular with our practice to suggest that it was a standing arrangement, but I'd intended to go practice by myself sometime anyway.
So, did I fail to 'show up' or did A get the wrong end of the stick here? A is one of my closest friends and I felt terrible that she was so worried, but I was also puzzled about why she turned up there without me confirming I was coming and then called my husband to ask where I was!