Do not worry. If you are talking to your child about guns and not planing an act of terrorism under the presence of talking to the child, you have nothing to be worried about. This is not Saudi Arabia.
This is not a stupid question at all and I understand why you are concern ed. There is a lot of conflicting media coverage about this topic. However, simply speaking about weapons is not an offense and will not effect your application for residency. Try not to worry.
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