AIBU? We visited my partners parents at the weekend and we took my 14 year old on with us so he wasn't on his own all day. My son is a little on the chubby side but working hard currently to rectify this, he's also very quiet, polite and sensitive. We arrived, my son walked in said hello to everyone and then sat on the sofa to play games on his phone, we told him to only cover one ear with his headphones so he would still hear what's going on around him. MIL walked in, made a comment about how he was wearing his headphones incorrectly then said "anyway, hi fatty, move over and let another fatty sit on the couch". I kept my mouth shut as to avoid making a scene on fathers day but took my partner outside and told him how angry I was. It was agreed he would deal with it the next day. We only see his parents about 4 times a year with the distance between us, MIL has met my son a handful of times in the last 6 years. I asked my partner yesterday if he had done anything yet to which he said he would sort it straight away. Apparently MIL is devastated to have upset anyone and just thought she was being funny, it was just a laugh yet she hasn't reached out to make amends. I don't think it's funny or was said in jest, the last 2 occasions of going to visit, when talking about my sons she has asked "which is the fat one and which is the skinny one again?". It only came out last night that my partner had never spoken to her before about this issue even though he told me he had. Now I'm not sure whether to believe he has dealt with this or not. I think MIL is being nasty and nobody should say something like that to a child, let alone one you are about to be related to, this is also the woman that on the one and only occasion I visited them on my own, she had a wedding photo of my partner and his first wife who have been seperated for 7 years in pride of place on the mantle piece, I've never seen this picture anywhere in her home in the previous three years whilst visiting. My partner and I are currently not speaking due to him backing his mum over this matter. Am I being over sensitive or am I right to be angry and upset for my son?