Holy fuck, guess I must've been trying to repress this one.
So when I was, I don't know, maybe 10 or so? I had very recently gotten access to the internet, we didn't have a computer before for whatever reason.
Being a bit of a dork I liked stories, and when I found out that there were online stories, about all kinds of things, even the cartoon shows that I loved watching! Wowee! (So you can probably see where this is going pretty quickly.)
So being a 10 year old I also was a big fan of toilet humor. Thank you terrible taste. I'm still trying to drown out the memories of my love affair with Adam Sandler (which honestly lasted way longer than it should have).
Aaaanyway, getting to the point, I found a porn fic. One of the trashiest sorts available. But to my preteen mind this wasn't sexy, or really all that disturbing, it was funny! And, whatever troglodyte was beating his meat while writing these graphic crossoverss had written cum as "come" in all of its usages. Being 10 that probably wouldn't have mattered to me too much but it becomes essential in my coming fuck up. Okay so for whatever reason I found the usage of "come" as something 'naughty' to be funny, and being a fuckwit of a 10 year old I still had issues telling when making dirty jokes was appropriate.
Fast forward a bit, my mother and I are going to the supermarket. I'm busy doing something stupid, reading a book, or playing with my gameboy, something. My mother gets impatient and asks if I'm coming or not. I tell her to give me a minute. She gets impatient and says that I can wait in the car if I'm not coming, slamming the door and walking off.
I run through the crowded parking lot to catch up, knowing that if I don't actually accompany her I'll get an earful later.
She's within ear reach so I shout:
"Okay, okay, I'll cum for you!"
And, being a little smartass, I thought a joke would ease the tension.
"Just not in my pants!"
She was mortified.
TLDR: Read erotic fanfiction when I was 10, thought cum and come being synonyms were hilarious. Made my mom look like a pedophile in a crowded parking lot.
(It was Sonic X Ed, Edd, 'n' Eddy for the curious, bet you need brain bleach now, huh?)