It doesn’t feel very good to be in a situation where you have a sense that you’re not wanted. Last weekend, I was third-wheeling with two good friends, and the whole time, I had a gut feeling that it probably wasn’t ideal for them to have me there. They weren’t being cruel to me, they weren’t excluding me, and they weren’t explicitly saying they didn’t want me there; I just knew that they’d probably have a very different vibe if they were able to talk freely amongst themselves. 

Most people don’t dare to say, «Hey, you’re kind of interrupting my hang with me and my closest friend. Can you please buzz off?» They don’t because they know it is cruel, and most people would rather grin and bear it through a social situation they don’t want to be in than be outwardly cruel to someone who hasn’t done anything wrong.