One night with my girlfriend we where doing it in the back seat of her car after our shared shift at work. (we worked in a bar so it was around 4 am) when sudenly some girl opens the drivers seat door (silly us forgeting to lock the doors), as i looked stuned at her my girlfriend yells close the door! in which case the stranger says sorry and runs away. How she thought that was her car i do not know, but needless to say we don’t forget to lock the doors.