When you're a semi-big boy and you take a poo poo in the shower and stomp it with your wet foot down the drain. This most commonly occurs in schools, but some retards even do it at home.
Disabled swim coach: Well what the kids are doing now is this thing called waffle-stomping, where they stick a turd on the shower drain and stomp it straight through... It drains straight to the pool... I've had to clean up 3 stomps this month.
Hall monitor Helen: Ay, no running youcock sucker.
The act of catching a wild Loughborough university in another city or town and proceeding to shit into a shower grate, pick it up and slap them round the face with it.
An act similar to fisting, it involves waiting until one party needs to defecate before shoving a foot up the ass of the person as they attempt to shit, stomping the shit back up into the intestines of said person.
'Yo, I heard Brandon gave Shirley a preemptivewaffle-stomp last night.'
"Really? That's fucking gross, I feel sorry for whoever has to wash his socks later on."