When a dick is inserted in someones ass, whether male or female, and the "dicker" pees a load in the "dickees" ass thereby filling and flushing it out.
So I was balls deep in my girl last night and then she slid it in her ass so I pissed and gave her a good ol' tranny flush
by Carguycolorado December 10, 2011
A strange sexual act that refers to a girl who was been menstruating for three days with the same tampon in. The guy positions himself under her and "pulls the plug"--this results in a very messy expulsion of red liquid much like when you remove the pan on an automatic transmission.
Dude! Last night my girl finally let me do a tranny flush, and it was so awesome as it gushed all over my face!
by Robbyb March 25, 2008