a place where people go to have sex at the top of a tall building and are almost caught when someone else comes up to it and immediately assumes no-one is on it. commonly used in anime and manga
Cummo: “Gee, check out the roof on Stoino, someone had a good summer.”
Marcus: “BOYS! Been hitting the lamingtons hard.”
Zamps: “Fucken oath, how’s the roof on it”