Name changed as could be outing. Will keep OP as brief as possible but don't want to dripfeed.
Due to get married end of 2018, DP and I covering costs.
DP had difficult childhood and still doesn't have greatest relationship with his mum, his Grandma was his support growing up, his mum tried to stop contact between DP and grandma after she fell out with her mum but as he got older he restablished contact and they are very close.
I get on ok with MIL to be but having seen first hand how awful she can be to DP I'm quite wary of her. I really like DP's grandma and have a good relationship with her.
DP's mum will be invited to wedding as will grandma. However MIL to be, will, without a doubt throw a hissy fit and refuse to come if grandma is there.
DP and I have said if that happens we will say fine don't come, no problem.
Are we being unreasonable being so black and white about it?
We have little tolerance for adult tantrums and grandma whilst NC with MIL to be (MIL choice) has no issue being at wedding with MIL, will suggest not coming so MIL will go.
Would you just say fine and not count MIL in numbers or would you try and cajole her into coming? Not inviting grandma is not an option.
Sorry that was longer than I intended, thanks if you read to the end 