Once cost me a night of carnal excitement
Met a girl at a club in London, things went very well and we're all over each other so I suggest grabbing a taxi back to mine... cue 75 minutes in a cab (normally 15 minutes) with the delightful-but-quite-prudish Mohammed insisting that neither of us can sit in the middle and definitely no leaning over to kiss.
By the time we got to mine, she was asleep and no longer in the mood for anything other than more sleep. Worst of all, it was surge fares so it cost a bloody fortune.