Oh, the it's/its thing is easy when you break it down.

it's = it is.
It's raining. It's on the table.

its = possession. (Yes, normally an 's indicates possession, but in this case, the apostrophe already has a job - meaning 'is'.)

The car can't go because its tires are all flat.
I can't wear this coat; its zipper is broken.

My dyslexia tends to play up with words that have a lot of vowels in a bizarre order or double letters and single letters that could be either way. For example, I just typed 'bizzare' and needed the spellcheck to tell me that was wrong.

And I wasn't trying to imply that I think Jack is *actually* dyslexic... more that he was lazy and Ianto was getting fed up with it.

Glad you liked the story. :)