St. John Morris said this quote

...his knees were held together by the skin-tight trousers, which consequently narrowed the aperture through which great quantities of malodorous, rancid dreck were shortly to emerge with great force. St John knew that this was likely to prove troublesome. Although his mid-morning bab was usually undertaken in a more perfunctory manner, he would still have been mindful enough to ensure that his trousers were well below the knee before he commenced the disagreeable act, but in his current predicament, he was in no state to dally.