Shitcum is what one does when in a state of extreme anger or rage; to shitcum in ones mouth is the ultimate act of disrespect. To do it requires a large will and steadfast self-discipline. The shit must be followed by the cum after no more that 3 seconds. While shitcum is normally placed in the mouth, it can be deployed anywhere on the body.
Chris: Dude, your girlfriend cheated on you? How’d you handle it?
Shitrum is a type of drink mixed between various type of liquors sourced from a young teenage boy's father's liquor cabinet. Various drinks are mixed together this way to prevent the teenager's father from noticing a substantial amount of liquid missing from the bottles, so mixing different types of drink together will result in a large quantity without the teenager's parents finding out. Typically consists of hard alcohol like rum, whiskey, and other alcoholic beverages. Shitrum is typically consumed with soft drinks to mask the 'shitty' taste of the concoction.
"Yo, Brad, let's head down to Tyrell's place and make us some Shitrum!"
"No one likes Shitrum dude, that shit tastes like cigarettes, piss, and soda."