There are a lot of moving parts here.

My parents and grandparents are fully aware of my lack of belief. So my parents won’t be shocked that my children don’t believe. I don’t mind letting e.g. my mother tell them about Jesus because realistically, humans believe what their environment believes and for my children, I am mostly their environment. So I don’t think some exposure to christian beliefs will have a bad influence and my counter-influence would be present, so my children can choose.

My so’s parents and grandparents don’t know about our lack of belief. Her mom is aware of my lack of belief in a religion. Now that makes the whole children thing more complicated but… We are a couple thousand kilometers away… So… I hope they accept that we don’t want to provide our children with any religious education until they are ready to understand it. So at an age at which children are able to lie in the worst case.