I'm probably being unreasonable but whenever there is a 3 way conversation I always end up being the person left out whilst the other two chat away to each other.
The main thing that bothers me though is if I ever see a friend and they are chatting to someone else (mainly on the school run), there is no way that anyone would ever even attempt to include me in the conversation. I just get a quick, smile-less acknowledgement or 'hi' and then they turn back to the other person. However if I am having a conversation with any friends and a third person walks past or comes to stand near us the friend will greet them like a long lost hero and they will be welcomed into the conversation and actively brought into it by whichever friend I am talking to.
I think what is upsetting me is a)no one ever is pleased enough to see me to want to welcome me into an existing conversation and b)no one seems to value my company or conversation in the same way and are happy to bring another person into any conversation with me.
It's just happened this morning again at the school run. Someone who I thought was a good friend has done this a lot to me lately and I feel a bit upset.