Green’s Dictionary of Slang

rural n.

In phrases

do a rural (v.)

1. to have sex in the open-air.

[US]Maledicta IV:2 (Winter) 195: A […] stargazer, which can also be a hedge-whore – that is one who goes stargazing on her back and receives an Anglo-Indian back. In other words, she has done a rural.

2. to urinate or defecate in the open.

[UK]Partridge DSUE (8th edn) 317/2: C.20.