I attended Yeshiva as a child and we were taught NEVER to walk into a church, EVER. When I was about 9, my very close friend invited me to go to Church with her. My sister, 2 years younger, went as well. I didn’t explode and it was interesting. I did not kneel, as I had been taught that Jews don’t kneel to G-d and I didn’t go up for Communion because I recognized that it would be wrong. My sister tried to kneel and I pulled her up. She ran up to the communion line and I tried to pull her back - it was such a scene. People thought she was trying to get communion early and just hadn’t been confirmed yet and they were laughing and I was too afraid to say we were Jewish. Flash forward, years later and my sister marries a Catholic guy, but at City Hall. After they got divorced, she converted to the Episcopal Church. Ironically, my sister-in-law also converted to the Episcopal church from Catholic. H and I joke that we are the only mixed marriage couple we know whose siblings are the same religion as each other and neither of them are the same religion as either of us!
For years, until she became non-ambulatory, I used to take MIL to church regularly. H refused to set foot in there. I felt that it was more respectful of my own religious tenet to honor my mother and father (and in laws) than to honor the rule I was taught to never walk into a church.