All of our dogs were expert farters. One used to fart whilst lying on his side, supposedly asleep. He wouldn't move but his stumpy tail would start to wag slowly, waiting for a reaction. If you sniffed, commented or choked, the tail would go into hyper-drive.
Another would climb onto my lap (all 80 odd lbs of him) while I was sitting in the lounge with my feet up, shuffle around until he was comfortable - usually with his arse wedged between me and the side of the chair and then go to sleep. It was OK for him to fart, but if I did (and I'd always try

), he'd get up, give me the dirtiest black-look imaginable and stalk off, huffing.