Anal sex is bad because it involves a blunt object stabbing at the direction of your heart. No wait. Its bad because Jesus is not recorded ever to have had anal sex either , so that's why. No wait. Its bad because requires you to relax your rectal muscles, which render you incontinent during the whole sodomical exercise.

Anyway, the subject is farting. I'd like to say discrete. If you do things discretely, nobody gets offended. Seriously, If you take an elephant dump on that new white couch while visiting the Joneses next door for tea, as long as you do it discretely, its no biggie. Discrete means you show in your behaviour that you are aware and careful with the people and their personal space around you. You are making sure that you do not disturb them too much. So fart, but do it discretely.