There is a brothel in Prague where the “services” are free, but live video streams of the “activity” in the brothel are shown on their website (for a fee).
[Wikipedia]

Male chimps, bears, dogs — indeed almost all mammals except humans — have a bone in their penis, called the baculum (photo is a raccoon baculum). No-one knows why it was evolved out of humans.

In the US, of those men who take paternity tests some 30% find out they are not the father of the child concerned – although of course these are cases where there is doubt to start with.
[Sheril Kirshenbaum, The Science of Kissing]