An individual who waits until the last possible moment before going to the toilet for a shit, thus not having to waste any energy in expelling said turd as it explodes out all by it's self.
What do you mean, you need a toilet now? you should have gone earlier, you lazyshitter!!
Whenever the tank and the toilet bowl are being used at the same time by two males, then while on the toilet bowl one turns around and blows the other dude before flushing.
Tommy said, "Don't go in the bathroom Mike and Steve are having a double shitter hitter."
Very similar to what is known as a "party pooper", but much worse. Someone who takes a massive hypothetical shit on the party, and completely ruins everyone's good time.
"The party was going so great, until Brian's girlfriend showed up. She completely shit on the entire party with her nagging and bitching."
"Damn man that sucks! She's such a Party Shitter!"