'Dogging' is where people gather, usually in quiet motoring spots or dissused car parks, to have sex. Sometimes in their car. Sometimes in the woods or somewhere nearby. It is a spectator sport where people do swapsy's and quite often single folks get invited to join in.
It is a seedy business and if you are unaware of it, maybe it is just in the UK.
![omgzokool :zoinks:](http://www.intensitysquared.com/Smileys/default/grinman.gif)