My partner has 2 boys with his ex, 3 and 5. They live with her during the week and come to ours on weekends. In the past my partner has had to speak with her about swearing at the kids, but when he picked the boys up today he noticed a scratch on his 5 year olds neck. When he asked him about it he said mommy grabbed him and dug her nails into his neck while shouting at him. This was Monday and the photo was taken on Friday. When we asked her about it she said he is lying and that she grabbed his arm to send him to his room, not his neck. There has never been any incidents like this in the past, but now I'm concerned and not sure what my duty as a responsible adult would be. Do I just monitor the situation? Do I report it? Thanks!