Would this bother you?

My Boyfriend's best friend who is a girl wears this mood ring he gave her on her 16th birthday. It's been like 5 years since he gave it to her, so I don't understand why she still wears it, also who the hell wears mood rings anymore? I told my boyfriend it bothered me, but he said there's nothing he can do about that. He claims she wears it ironically because she wears it on her middle finger. It bothers me so much but he's made it clear he isn't going to do anything about it.