In a railway station!
More unusual that it was a heritage/preserved line, running steam trains. The carriages were all individual compartments, each with their own separate door, with droplight windows.
Boarding the train at one end of the line, we got a compartment to ourselves and stuck our heads out of the window, me standing behind her. An elasticated waistband allowed easy access to my hand and she orgasmed as we pulled out of the station.
Sue always wore stockings, usually with suspenders and, heels. So, with a little bit of wiggling, I was able to enter her from behind.
Whilst she had another orgasm, leaving the next station, I couldn't quite find the correct angle for MY pleasure.
At least it saved having to deal with a sticky mess.
