just to make you feel better, I once did an enormously loud fart in yoga while I was demonstrating a position to everyone else. I was sitting down, with my legs held wide apart, one foot in each hand. There was absolutely no chance of hiding it, everyone was looking at me and it was a proper rip snorter!
However, when the others tried the position, at least 3 of them farted too, so I felt much better!