Now with less illegality
This, from an article on the Joy of Sex in today's Guardian, made me snigger like a schoolboy:
The first edition of the Joy of Sex considered sex on moving motorbikes. "If you have access to a private road, the hazards are yours," counselled the book's ironically surnamed author Dr Alex Comfort. Thirty-six years and 8m copies in 22 languages later, that passage has been excised from the New Joy of Sex. Funless if sensible safety legislation has since made sex on moving motorbikes illegal. Doing it on horseback (as mentioned in the 1972 edition) is also outlawed. So stop that too.
If you'll excuse me, I'm off to cancel my next riding lesson...