One-on-ones I can handle as long as the other person initiates the conversation. I'm not very good at initiating myself. Three people is ok but it's awkward if the other two talk about something I can't give input for.
For example, the other day I was in the hospital to see my mum who had just come out of surgery for an eye operation. I wanted to be there to support her, but her very talkative friend also came. So what ended up happening? Her friend talked to mum about 95% of the time we were there, and I couldn't say much because they were talking about curtains, the neighbours, their pets, the weather - all things I could only make little comments on at the most. I have the feeling now that the friend doesn't think much of me, because a lot of the time I was just listening to them talk without offering much input. Plus I don't know what mum thinks, but I'm sure it's not good either. So, sometimes three people is too much for me.