So, 'gumping it' is when someone is not quiteretarded, but they're like just on that line.
"I need to confess a sin, Father. I worked at a grocery store in my teenage years, I won't get specific. There was this one girl-- are you familiar with the term 'gumping it' --so while it's an ethical conundrum, it's not fucking a retarded person if you were to sleep with 'em. This will come important later in the story..."
From the verb "to gurf". The action of eating fast and gulping at the same time. Popular word amongst Twitch streamers and vtubers like the infamous CodeMiko.
The act of getting chewing gum from your pocket, bag, place of storage, when surrounded by a large (or if you're greedy, a varitably small amount) of people, as so that the surrounding people do not notice you have gum, and hence will not request gum from you, depleting your store that was meant for the next week and a half.
Guy 1: "I see you have a fair amount of Gum there, Guy 2."
Guy 2: "Yeah, I've been Sneak-Gumming all week! Them vultures don't got nothin' on me!"
----
Man: "*Chew*"
Everyone: "GOT GUM?! GIMMEGIMME."
Man: "Damnit I've never been very good at Sneak-Gumming".
One day, for no particular reason, I decided to have a little beer. When I finished the beer, I thought i'd drink another. By the end of the night, I drank 47 beers and passed out. I sure was Forrest Gumping!