Dogging is a British term meaning having sex (usually unprotected) in a public place, typically a park. The people involved often do not know each other. Sometimes, there are more than two participants, making it an orgy. Observers are often encouraged, thus making dogging a form of exhibitionism.
The act, if not the term, is common throughout the Victorian novel My Secret Life by "Walter", though it happens throughout Walter's travels in and out of the UK.
Health officials fear that dogging is leading to rising instances of sexually transmitted diseases.
In September 2003, the BBC reported on the new dogging craze. They cited the Internet and text messaging as very common ways of organising meetings.
Another definition of dogging, which is related, is the act of spying on people having sex in a car or public place. This can become a habitual thing, and some people even start clubs, earning points for how many different people they can view etc., etc. In fact, persistence generally, especially following someone closely, is called dogging.
Dogging has no connection to dog play.