A fart smack is when you sneak up on an unsuspecting sleeping friend or foe, squat over their slumbering face (pants optional) and unleash a large, preferably disgusting odored fart. Swiftly after you must wake them up with an authoritative smack to there face. Thus waking them up to a big, startled gasp of ass gas.
The type if fart that emonates up through you butt crack while you are sitting down. It pauses monentarily and then lightly fluffs past your ball sack. The fart is complete...
A sack fart is when someone farts on your ballsack to create a pleasant warm sensation. The giver of the fartmay be male or female, and this process is not neccesarily sexual.
Please note, a sack fart is only present when you can smell the fart with your nose pressed to the ballsack. When the smell expires, the ballsack loses its' title of the sack that doth hold the fart.