I had a similar moment at Charles de Gaul airport. Leather seat, echo prone gate area (the echo stopped people pinpointing the sound). I did the only decent thing; looked over at an old lady near to me tutted loudly and moved.
Also had a comical urinal moment. In the pub over the road from my local train station, in the loo and a bloke runs in at full speed. Clearly drunk but obviously busting. Having made it from the station, across the road, down the stairs in time, he unzips and pisses in the corner of the room not in the urinal. Never worked that one out.