Does anyone know the short story called “shit yourself”?

I’m not 100% that’s the title, but if you’ve read the story I’m pretty sure you’d know it.

The premise is a stranger convincing the protagonist to shit themselves. Despite the crude premise it was really well written and funny.

I’m asking here as I’m sure it was on the blog of someone who mostly wrote about tech stuff, possibly front end dev or UX?

I’ve been trying to find it for a couple of years with no luck