The latter. Religion is family to most people of our collective ethnicity.
I dated, lived with, and proposed to a white atheist over the span of three years. I never told my parents because it would literally kill them.
They knew of her, and they probably knew something was going on, but as long as it wasn't said, it could be brushed aside. That's how this culture works with some people. I feel like newer generations are probably going to be better about it, but our generation still has to suffer a lot of it.