Babysitting sounds simple in theory — until reality shows up in the form of diapers and deception.

For one inexperienced teen, agreeing to help his brother turned into an unexpected crash course in potty training.

And it’s where he finally drew the line.

Keep reading for the full story.

Am I in the wrong about saying I won’t babysit unless his child is potty trained?

My brother asked me to babysit a few days ago, and I said yeah, why not.

What I didn’t know was that his 4-year-old son wasn’t potty trained.

His brother left him vague instructions on how to monitor his child.

My brother said to keep asking his kid every so often if he had to go potty, so I did.

Every 20-ish minutes I asked the kid, and he kept saying no, so I said, “Do I have to check?”

That’s when the truth came out.

He then responded with, “I messed myself a long time ago.”

I’m 19 with no younger siblings, so I’d never changed a diaper before until a few days ago.

This task was even worse than he imagined.

It was a 4-year-old’s diaper, so you can imagine the smell (I sprayed Febreeze while wearing a mask and still almost puked 4–5 times).

My brother then came home, and I said, “He lied about it, and he said he messed himself after I asked him about 10–15 times.”

Turns out, this was a normal thing that his brother conveniently forgot to mention.

P said that his child lies about it and that it’s a normal thing.

AITAH for saying I won’t watch his kid unless he’s potty trained?

This seems like a legitimate boundary to set.

Did Reddit agree?

This commenter thinks this 4-year-old is a bit behind in this aspect.

Perhaps this is all part of a troubling new pattern.

These shortcomings tend to fall directly on the parents.

This user draws the line at diapers.

This changed diaper changed his whole stance on babysitting.

And this lesson came wrapped in plenty of Febreeze.

If you thought that was an interesting story, check out what happened when a family gave their in-laws a free place to stay in exchange for babysitting, but things changed when they don’t hold up their end of the bargain.