We have said for years - Don't take children swimming in polluted waters - for some of the reasons you have stated. It's also not clear that a lack of sexual activity is harmless: among our closest non-human relatives (bonobos), sex play is widely recognized as reducing stress and increasing community bonds - both of which contribute to better physical health. In our current environment (enforced stupidity), the risks usually outweigh the benefits - but it is not at all clear that this would be the case if we were not in the midst of a moral panic.

But really - your post is a rather ham-handed way of pointing this out.