Hmm. This is a pretty interesting first person article you got here. I liked the beginning, and it was pretty strong throughout. You introduce the narrator's different embarrassing minor "crimes" against Mr. Johnson very nicely and appropriately, I had no complaints there. The only part I'm really questioning is this last couple of lines at the end of the second to last section, "I bet he wants to lick my asshole. Lick it real good till it's good and wet and then plunge his cock deep inside. Faggot. Yeah, you too! You're both fags!" On the one hand, it's great. Immediately after this, we discover the ironic twist at the end, that the narrator is actually talking to his grandmother. Something as graphic as this makes for a great punchline, not to mention a second layer of humor which goes back to our questioning of the narrator's sexuality. But on the other hand, perhaps the graphic nature of this line is just a little much. I mean, sure, that's the joke at the end, but at the same time it may come across as being a desperate attempt at getting shock laughs from 12 year olds on the internet. I'm not going to try to sway you either way, and I'm not going to take away points for it.
As a whole, the article doesn't change up too much in its jokes. This is probably due to its nature as a first person article, making it hard to get a lot of material out of it. But at the same time, I think it's a good length. You're not trying too hard, and you're still pretty funny right up until the end. I would usually give this a higher concept score, but I remember voting on an article very similar to this one.
Prose and formatting:
The prose is great, you were nice and consistent throughout this article. Sure, it was a little on the short side, but who cares? It'd have been hard to keep going with this concept while still staying funny. My only beef with this section is your headers. Why are they all level one headers? Usually, they're level two headers in most articles. I can't think of any situation where you would use level one headers. A very minor and trivial issue which won't take long to resolve, should you choose to.
Your images were fine, good number of pictures, good captions. My only problem here is the size. Try enlarging them some, and find a size that doesn't fuck up the text wrap too much. Other than that, I got nothing for you here.
Overall, I'd say this is a strong article that certainly elicits some laughs. Sure, it could use a little polishing up. But my only real complaints about this article have been formatting issues. The rest seems pretty solid to me.