Duh

Not what I would call a shock:

Swinger Shock: Older Age No Defense Against STDs

Those Who Engage in 'Swinging,' Even at an Older Age, Have High STD Risk

According to the article, these older folks are somehow clueless about the risks of condomless coupling with friends of friends.

You can see how something could spread quickly in such a sharing group.

Swingers who neglect to use protection,
can expect an unpleasant infection
circling in their direction.