Can we also show our bitcoin key to someone closer, maybe love, spouse, next of kin?
Better still between someone; who introduced and taught you about bitcoin, a friend or family member and your children who's most preferred and reliable person to give out our information about your bitcoin?
I think it depends on your decision, you might decide to tell someone your private key and you might decide to keep it as a secret, you can come here to ask people who you are to share your private key with, if I will advice you, I will ask you to keep it to yourself, when it comes to money, nobody should be trusted, even if it's your family member. But if you really want to share your private key with anyone, then you should decide yourself, you know people that can be trusted and the once that can't be trusted in your family, so I think you should look for the person that can be trusted.
Totally agree, we can only rely on ourselves compared to other people, but all decisions depend on each one because the assessment of trust is very subjective based on each other's opinion, the important point is who can you trust your bitcoin private key and he never betray you, the answer is in your mind so only you can make that decision. But remember that whoever has the private key of the wallet owns it.