NAH. I grew up in a community where some people went to church and some people didn't. When I went for sleepovers at friends' houses who went to church, I went with them even if the denomination didn't match with my family's. When kids who didn't go to church came to mine, they went to church on Sunday morning. The way I see it is you gotta ask about things like church, if you're really opposed to them, and then you have to arrange to pick your child up before they go to mass so there routine isn't altered, if you're intent on the sleep over happening. They took on two 8 year old friends for the night and gave you a little break until the next afternoon. Essentially, you can't expect them to miss church, which would mess up their routine and possibly put them in a position where they feel like they are compromising their own morals to accommodate you.