A good friend of my family is currently going through a divorce from her (financially, physically and sexually) abusive husband and facing stigma for leaving her marriage in India so I suggested she come visit me for a short break to get away from the horror at home.
She has 2 sons, who are 6 and 13 years old. She mentioned that they are scarred by the father and she's working on their anger issues so that they don't grow up to inherit these traits too.
They've not been angry or aggressive in front of me but I noticed her teen son has a bad habit of constantly fat-shaming her and putting her appearance down . This is especially odious because she's lost a lot of weight due to the trauma she's faced in the past few years and is the thinnest I've ever seen her (UK size 10 or so).
Her son particularly irritated me yesterday when we went out for dinner and he pointed to a very slender woman in a crop top who was carrying a baby and said "look mum, her baby is so much younger than your baby (his little brother) and she is so toned but you're still so cute and chubby." This was around the 10th time he has brought her weight up in the few days he has been here and he's also remeninded her to conceal her under eye circles on another occasion before we left home. And my friend keeps humouring him and making fun of herself when he does.
I don't want to blame him as he probably internalised this behaviour from his dad from a very young age (and he has been through a lot himself too) but is there a positive, non accusatory way that I can point this out to my friend and tell her how to correct this unsavoury habit of his?