FurtherMaths,
Ahhh, one of the many questions and situations one must face being a pilot. When to sleep, when to eat, adjust to local time, stick to Singapore time, when to fart, when to clear bowels.
In time, you will learn to face these situations, my young Jedi. But, believe me, don't think you can get away by letting it silently rip and innocently look around with a shocked look on your face acting as if it weren't you. Especially when there are only two of you on the flight deck.
Anyway, the toilet is there to be used. And, avoid durians before flights.
