ILs and I fundamentally disagree about religion (they're strict Catholics, I'm atheist). After a few heated exchanges when DH and I first got together (instigated by them) we've all silently agreed to a truce where we usually just don't mention it. Fine by me.
The only time it comes up nowadays is when they pester us to send the DCs to Catholic school. And also when they want the DCs baptised. And when they want us to go to church at Christmas. So actually, thinking about it, quite a lot. I have a standard response which I use to shut the conversation down along the lines of 'I'm not going to argue/explain why that's not happening because we won't agree and we don't need to agree as it's a decision for DH and me only.' This is usually enough to halt any potential argument, albeit with bad grace from their side.
We have a WhatsApp group with DH's immediate family. Tonight MIL has sent a joke about atheists that I find really enraging. The inference of the joke is that atheists are smug and stupid. MIL has followed up the joke with an explanation that she finds it so funny because the atheist subject has been 'put in his place' for 'thinking he knows best.' No acknowledgement that everyone with an opinion 'thinks they know best;' that's what faith or belief is!
For some reason it's really pissed me off. I want to say something. Maybe point out that I could reverse the joke to make it the same point against Catholics, but I wouldn't send that to her as it would be rude and upsetting to her.
For context, the group is MIL, FIL, their 2 adult DC and me. Neither DH nor his brother are religious, so it's not like it's a part of a family culture they all share that I've come in to. Also for context, generally aside from this we have a good relationship.
WIBU to say something? Is it the job of the DIL to step back in this situation because it's not 'my' family? Or do I have just as much right to say it's rude as MIL does to say it?
If this was a one off I'd let it go. It just feels like a constant imbalance where the only reason we aren't constantly arguing about this is I've learned not to react, not to retaliate, ignore and be nice, but to be honest I don't see why that's my role.
They're people who take great offence to being called out or criticised, but are perfectly happy to share their strong opinions themselves. If they were my friends I'd take a 'sauce for the goose' approach and say my piece, but am I expected to act differently because it's my ILs?