Ass Cum
1. Unpleasant result from anal intercourse in which the cum leeks from the anus, discolored with feces, and chunks of feces.  Can often lead to Anal Cream Corn.

2. A mutation in which the Vas deferens are routed to the rectum, resulting in ejaculation out of ones asshole.
1.  "Dude you just farted ass cum back onto my dick"

2. "I just blew a load of cum out of my ass", says guy 1
   Guy 2 retorts,"That, my friend, is what we call ass cum."
   Guy 3,"mine usually comes from my dick."
   Guy 1 states,"My semen always came out of my ass."