The
act of passing gastric wind directly from one anal cavity to another which is subsequently re-released by the receiver.
The 'fartee' bends over and parts his
arse cheeks with his hands revealing a gaping anus. The 'farter' then positions his anus against that of the fartee and breaks wind directly into the fartee's anal cavity. The fartee then clenches his anus shut thus
trapping the wind of the farter. In his own time he then releases the
fart as if it were his own. The fartee has become the farter. This is a back door blowback.