You shouldn't go to a yoga class!
Fair enough that the odd trump occasionally pops out (never happened to me but can see that it might) but to fart on and off throughout the class at every change of position I think is fairly grim.
Bearing in mind we are trying to avoid peoples oral fumes, I don't want to spend 50 minutes breathing in their anal ones!
Before I get attacked by people mentioning physical problems that may cause gas, I have suffered from IBS in the past and would not attend a yoga class if I knew I was having a particularly bad day.
YABU - Everyone can enjoy yoga, even if they are tooting throughout the class.
YANBU - that is grim.