Brief summary about myself. I work in IT and often enough people ask me to help them with their IT related issues, most often it's someone from the family or relatives. In my every day work I do a lot of tech related things, which means some things to me seem super obvious or super easy to do, when for some people they're not. consciously of course I know that, but I assume that the problem that I have is influenced by my subconscious. There are times that I'm easily "triggered" by people not being able to understand what I'm telling them or how to do certain IT related things. I'm trying to work on my behaviour and I think it's much better than before, since I'm catching myself a lot of times not saying something, when I would have before and things like that.
This case is a bit different. I have a little brother that's 5 years old, he comes sometimes on the weekend and I really enjoy spending time with him, since he's a little fun kid and he really loves playing computer games, he doesn't have a computer himself, so being able to play at my home is like a birthday to him. Recently a couple of times I've noticed that I'm getting angry at him for things he does not understand. I'm not talkin about any kind of physical threats or whatever, just that my attitude kinda changes for some reason, last couple of times I managed to not get angry, but I still feel that something is not right and I'm afraid, even though he's a kid, he feels it too.
He plays racing games on my computer or some other games for kid and usually he fails, since he's absolutely new to the computer and is a little kid and when I explain to him what to do, show him what to do multiple times, even though I do not get angry I'm still somehow not okay, I start to be distant or cold or whatever the word is to describe that behaviour. Afterwards it's still okay, we have fun etc. when he's not playing and it's like it never happened, because he also forgets stuff, since he's a kid, but when he leaves, I feel kinda gulity and I don't want to put him in a position that he's in the environment where he can't make a mistake, because that's definitely not going to help him. I know that the problem is only in me, him being a kid has nothing to do with my issues.
My question is, how do I show him that it's okay to make mistakes without looking angry/frustrated or expressing anger or frustration at him?
P.S. If you can recommend any books on a similar subject or issues that would be even more great, thanks.