Welbeck, could it be that the Grans you saw were not being unwelcoming, but so caught up in the conversation, they were oblivious of you.
How would they know you wanted to join them , unless you introduced yourself to them?
I know what the last Glasgow meet up was like, we were so busy, noisily chatting, that we wouldn't have noticed a bomb going off.
We all made a point of checking every so often, just in case some one was looking for our group, but nervous about approaching us. It's two way thing.
I think it's disappointing and sad that you felt the Meet up was such a negative experience. It's not easy, but as I have said before, you have to be proactive and sometimes have to make the first move.
I give the impression of being confident and very chatty, but the reality is that inside my stomach was churning at my first Meet up, but I thought I had nothing to lose by going.
I'm so glad I did, I have made some lovely new friends.