I think I read the first post differently to everyone else. I took it as she was concerned for the step mum because her husband is manipulative. I've got friends who are step parents and friends who are separated. And I know the parents would want to be a part of extra curricular activities, not to exclude the step parents. Not because they love the child more or anything horrible. And not expect the step parent to do it, it's not offensive to the step parents unless either parent is incapable. No one is suggesting that. I asked DH and he said that if it was him he wouldn't want her to do it so she could enjoy that special time. Not because she's an invalid. But because it's a special time. His second comment is he'd want to be at the lessons himself. If it were unavoidable sure. But in all the shared care situations we are privvy to unless it can't happen both parents prefer to be a part of these situations. It's not to be offensive, they are their parents. Why wouldn't they want to be there?