Remember that scene in Fatal Attraction where Glenn Close rides Michael Douglas as they’re taking the elevator to her apartment for some a weekend of sex and wrist slashing action? Perhaps there’s a little Glenn in all of us. Elevator sex is all about spontaneity and risk - and more than a little bit of exhibitionism, perhaps. After all, who knows when the door will spring open - and who will be waiting on the other side? Work out the ratio of storeys to how long it takes you to cum - and scale the heights of pleasure.