Yup I have... was a Saturday morning and me and a coworker were the only ones in the office - which was on the 12th floor overlooking the Houses of Parliament. We'd been flirting for a while and one thing led to another and we ended up having a lovely time in the managing director's office and board room... was a thrill to have her up against the window, thinking possibly someone could look up and see us. Sadly it was a total one off but still awesome fun.