Well from now on when I go to the toilet i'm picking the one next to someone. One day I hope to be going to the toilet next to you. You know what's really fun when you start talking to the person next to you. Or start asking them to pass you some toilet paper.
Op I think they were rude. More then likely the sort of mums that think they own that spot. I would have gone up and sat down with them and started talking over the top of them.