seeker I'm beginning to envy you your DSC, they sound so well balanced and reasonable!
My DSC, like many, are on the lookout for any possible indication that I might, in some way, possibly, be even considering being critical of their mothers choices. It's quite understandable - they don't want SM to measure up to, or worse, be more favourable in any way to their Mum, so believing that SM is criticising their mum is a good way of justifying their own defensiveness. Some DCs are primed to expect negative remarks from SM about their mum - and in these cases, a SM really cannot win.
If SM works full time and mum doesn't - any conversation about SM job is interpreted as criticism.
If SM stays at home and mum works - any plans SM makes during the working day is critical.
If SM cooks, cleans, sews - but mum doesn't - SM is in the wrong if she does those things for the benefit of DSC 
The mere fact that a SM asks a DSC to do something that they are not expected to do by their mum is often enough to imply criticism of their Mum.
OP - it sounds like you've got bigger problems than a grubby child if your DP is a DisneyDad and you are being expected to fulfil a parenting role 