The act of giving yourself a handy while taking a glorious dump resulting in Humpkin.
"Fucking woke up to my roommate taking an orgasmic shit in my bathroom. Seriously going, and I quote, "OooOoooOooh OoOh OoooooooooOooOoOoooHhh oh". Had to hit him with the "give yourself a Humpkin in your own bathroom"...he then proceeds to finish and walk out without washing his hands.
The act of taking a shit on the person while recieving a blowjob.
Comparable to a Blumpkin, but this act involves the poo to go on the person rather than the toilet.
It is a Human blumpkin.... hence, Humpkin
Only people who are disgusting do this lol... It a bit off from a Cleveland Steam Roller
Girl 1: I dont know what to get my bf for his birthday.
Girl 2: Just give him a blumpkin this year.
Girl 1: I did that last year, I need to up it
Girl 2: Give him a humpkin
Girl 1: A what?
Girl 2: Give him a blowjob and instead of him pooing in the toilet he'll poo on you.
Girl 1: That's a great idea!
A sex session like a grumpkin in which one sits on a toilet taking a shit while another person gives the shitter a blow job; during a humpkin the grumpkin reciever humps the grumpkin givers face while holding the back of her head; hence HUMPkin.
"My you really humped my face while I was giving you a grumpkinJimmy."
"Ah yes, cynthia, I did not want you to do all the work my dear. That was a humpkin"