A woman I work with has a really annoying habit of moving her thumb joint so that it clicks. She does it ALL THE TIME, if she is just sitting down, in a meeting or chatting. It is a tiny sound but it completely grates on my nerves. How can she not know it's annoying?? I know there's nothing I can do about it as I can hardly say 'Can you please not click your thumb, it's incredibly annoying', can I?
She is perfectly nice apart from that, but AAARGH. AIBU that it annoys me so much?