When children are growing up, they need to feel safe in their own home, and that none of the visitors to the home will act in a way that worries them or invades their privacy or personal spaces.
Children read body language, and instinctly know whether they are loved by their parents. Self-esteem builds when parents spend a lot of time helping their children to grow up feeling loved and wanted and able to spot opportunities to earn money and get the things they desire.
Parents need their space/privacy for adult activities, but parents also need to spend quality time with their children. When children feel lonely and sense that their parents are too busy to spend time with them, they start drifting into gangs for the emotional support lacking at home.
I can't see any advantage in telling children all about "adult activites". It is better to live in day-time-compartments, and tell them on a "need-to-know basis", so that they can be kids as long as possible.
A couple of family generations ago, it was the social mantra that girls should not be given a sex education, and that anything they needed to know about sex would be taught to them by their husband on the wedding night, because "hubby would own her like a chattel until death do us part". And to top it off, if she did not obey her husband, he had the right to spank her bare bum to "bring her into line". Sometimes, a wife got a weekly paddling to "remind her to continue to be good" ("preventive medicine").
In recent times, females have OFTEN turned the tables and become the spankers, and the husbands the spankees to keep the "men in line". Which actually makes a lot of sense, because, quite simply, men in general struggle to understand the true needs of women.
By giving up the struggle, and obeying your wife, she can let you know with her tongue (or the whip) if you have failed to please her.
It is always better to take a good spanking over her knee, than to have no sex with her for months because you have upset her. Take your medicine, and all is forgiven.