I was thinking more like the "Stalker" fart. You know how it goes. You leave the room and politely fart in the bathroom. But to your horror, on return to your guests in the lounge, the fart has been carried along in the slipstream.
No, seriously, after consulting the Dictionary of Farts, I think it was this one:
Not Now! (a.k.a Anal Control Fart)
You feel the presence of a mighty fart, and are unable to release it due to your situation. Happens on first dates, at important meetings, and on other such inexcusable occasions. You clench your buttocks together so hard that you nearly give yourself a stroke, and wait for the pressure to subside. Success depends on a number of factors, but Sods law tends to win out in the end.