I meet up with a close friend every few months. We get on well but I am getting increasingly annoyed with her interrupting me when I am speaking. I will be halfway through saying something and she will suddenly notice something and say (for example) "oh look at that dog, it's so cute" Last time I was saying something serious about my mum dying and she just switched subject, pointing at a poster on a wall that showed a band we both like and saying their name in an excited voice. AIBU for letting this really annoy me? What would you do?