I should say from the off that I have a very good relationship with my MIL. Apart from this one issue, I think she's absolutely wonderful but that almost makes it harder to broach the subject. She keeps on saying "my baby" when referring to my son and it's really getting on my nerves. He's not hers, he's mine! I may have a touch of precious-first-born syndrome here but still... AIBU or should I say something? If so, how?!