You know, I'm really sorry for the hassling you're having to endure and all... but for some reason this statement has really caught my fancy and I can't stop laughing. I think it's the "Hey boo" part. I've never actually read that term, only heard it in movies and TV. It doesn't fit my "mental image" of ya.
maybe your gf really knows the person, but in front of you acts like its some random caller harrassing her