I’m (hopefully) not ever straight-up rude, but I do refuse to engage with anyone I don’t like.
On NYE, we had a soiree at my friend’s house and he politely invited his neighbour. She turned up and tried really hard to make us watch White Chicks on DVD. She’d brought it with her. She tried to talk to me a couple of times and I just gave single word responses with a smile and walked off. Bit rude, that. 
(so pleased I got to use the word soiree)