How long into the relationship do you wait before you start farting in front of them?

You're question made me wet myself laughing! It's so bloody forward but it's also a natural thing to wonder about! Hahahahahaha! In my relationship I was thinking the same thing! I'd have to fart and I'd be thinking "Is now the right time yet or should I wait another month?" Didn't have a choice that night though, I bent over and out it came! Couldn't do anything but laugh it off and I was MORTIFIED! =P