Me and DH married a year, together for 3.
Never had a problem with his ex who he shares a child with and I get on really well with DC.
The other month he had to run an errand when he had DC, it was unfortunate timing but it was urgent and couldn't be helped. I offered to watch DC whilst he did. He was only gone a maximum of two hours.
His ex kicked off massively about it saying DC is not mine (which I never implied they were) how dare he leave me to look after them, I'm not there mother etc...
Fast forward to now (a month later) she has plans on a day where she is supposed to have DC and has asked H to swap a day. Unfortunately he can't due to work commitments and so she has asked if I will look after DC.
I have absolutely no problem looking after DC, this is not about them in any way but I want to say no.
She wasn't happy about it before and made it clear, I hate that I'm now just seen as a convenience because it suits, I don't want to be a mug. By the same token, I don't want to cause drama or hostility!
Wwyd?