So a bit of background. MIL and I have a very forced and false relationship. She is very snide and often makes comments that are out of order. She is gossipy and has a fairly close relationship with my husbands ex (they have a boy together). As a result of this I have distanced myself from contact with her and keep to the bare minimum. It works for all concerned and stops me getting wound up by her nasty comments and behaviour.
MIl looks after our DD2 a couple of times a week. This is her desire as I would prefer DD to be in nursery full time. She undermines with toilet training etc (putting her in nappies when she is dry now) but I understand the importance of a grandparent relationship, so besides a dig at DH when he brings her home in a nappy, I let it slide. It's not for much longer anyway as school is only just over 12 months away.
Anyway to my AIBU. My stepson mentioned the other day that his school are doing afternoon tea for mums and grandmas next week. He then mentioned that he would have to serve tea and cake to his Mum, Grandma and sister! I questioned why his sister and he said that Grandma is bringing my DD to his school to celebrate Mother's Day with my DHs ex. Now it's worth mentioning that The ex is has been a pain the arse throughout our relationship. She barely looks after her own son. He is with us most of the time. Even today on actual Mother's Day she doesn't want him home until later on (she has 2 other boys who will be with her, but has not requested SS to come home early!). She has never spoken a word to me even when I have arranged her sons birthday party etc. I don't want her around my DD. Yet MIl thinks it is appropriate to take my DD. My position is that if she wants to celebrate Mother's Day with his ex that is fine but not with my daughter in tow. Grandad also looks after her so I don't understand why she wants to take my DD when she can stay at home. I think it is completely inappropriate and given MIL past behaviour, it's being done on purpose. And she has never asked or mentioned it so she knows it is wrong and I wouldn't like it.
DH doesn't think it is a big deal. I asked if it was the other way around how would he feel, if I snuck around and took our DD to celebrate Father's Day with my ex, would I be out of order?
He has said he will tell his mum that I don't like it but I think he should tell her it's not appropriate and neither of us are happy. Otherwise it makes me out to be the bad guy when it is actually her that has put me in this position of saying no. AIBU?