connecting ones own mouth and anus via rubber tube, promoting feces to travel between the two orifices. The literal ass-to-mouth.
Guy 1: Dude!
Guy 2: What?
Guy 1: I just did a san francisco transfer
Guy 2: Get the fuck away from me and brush your teeth
Guy 2: What?
Guy 1: I just did a san francisco transfer
Guy 2: Get the fuck away from me and brush your teeth
by junglebunny420x September 22, 2011
Get the san francisco transfermug.