Formalized voyeurism, where couples have sex in public places, often spots that are known for dogging. Couples who like to be seen having sex will sometimes log onto dogging forums and announce the time and place where they will be having sex, often in their car. Spectators who show up get to watch and stroke themselves into a frenzy. The sex is always consensual, and people who show up at dogging sites will sometimes throw convention to the wind, with males who identify as straight occassional having sex with other males as part of the dogging scene. Dogging has also been common on trails and other public places where gay sex occurs. Make sure you aren’t violating local laws and ordinances about sex in public. Started in the UK and still seems to be more popular there than anywhere else.