Dear Dáithí: My mom brings our kids to mass without asking us

We all love our grannys, and we must mind them, but this is not on.

Dear Dáithí, 

My husband and I have two young children – a boy aged 6 and a girl aged 3. When we had our son, we decided not to have him baptised – we’re not religious at all, haven’t been to mass since we were both living at home with our parents. We’re more than happy for our children to make any decision they want to when they’re older about what they believe in, but for now, we speak to them about other religions and talk about how we believe in being kind people. The thing is, my mom never agreed with our decision, and recently our son has told us that she has been bringing him to mass on the occasions that he’s been with her for the day. Now we don't particularly have a problem with that as such - she is very religious herself - but she is doing this without asking us. But what drove me to write this letter though is that she recently told him that if he doesn’t believe in god, he doesn’t believe in love, and it’s upset him (and us!). I’m so angry but I don’t want to want to lash out in anger with this one. She’s a wonderful grandmother and loves spending time with our kids and they love spending time with her, so I want to tread carefully here, but also, I really want to put my foot down. How do I do that without alienating her?