I have intensely rational reasons for all of these.
Some are made up, some are commonplace, but all are completely legitimate. Or as I prefer, Legit. Which they are.
Buttload: A large amount of something.
Cubic Buttload: An extraordinarily large buttload of something.
Douche, and all of its variations, 'like such as' douche, douchebag douchetastic, douchey, etc etc.
Douchecake: This one is set apart from the rest, as it is a special brand of insult. It is a careful combination of the words "douchebag" and "fruitcake." As much as I would love to take credit for the creation of this word, I cannot. Though I am eternally grateful for he who did.
Fruitbag: ..............eh. Just kidding about this one. It doesn't seem to work as well the other way around.
"For shiz lagit:" Pronounced "fore shi[z] lag-it." Not 'legit.' 'Lagit.' Generally used to express Astounding reactions to something that has occurred.
i.e. "He did whaaaaat last Thursday? For shiz lagit?"
"I don't know nothing bout birthing babies." Commonly expressed by Erin in the place of simply saying "I don't know." Famous quote from "Gone with the Wind." Generally expressed monotonously, accompanied by a deadpan look.
"Shut the front door!" Used as a substitute for a similarly close phrase, to express indignation.