Well, not quite, fortunately. But I was priveleged enough to see it happen to a buddy at Jr. High summer camp.
You see, when you fart, the air is initially exhaled from your butt, but at the end of the gas passing, a slight bit of air is "inhaled" back into the bootie (kinda like backwashing when you're drinking), so if you're holding the lighter too close, well... uh... It can hurt, and cause some slight damage to the uh...
Butt.
But the initial fart is really still worth it, at least to your buddies who can actually see the action back there, as you can really get a nice flame going with enough oomph.