You know that childless couple? They have been together for years. They are your neighbours or your friends. They are in your family or you might have just met them.
Don’t ask them when they are having children.
They could be enjoying each others company and planning on kids in a few years time. They might not want children. They may be trying and have tried already for three years.
Whatever their situation is, they don’t want to hear that question. They are sick of hearing that question. It could be a mere annoyance or a dagger to the heart.
So don’t ask. If they want to talk about it then listen, but don’t ask.