It wasn't just the tech it was how I was telling them to do something. I gave different instructions to them about how to accomplish a task and he gave them opposite instructions while interrupting me. That's confusing to students do they follow my instructions or his instructions. I had reasons behind the method I had them use. That was the first time. It's not just how I appear that while I care about it some, it's more that being interrupted like that throw's me off when I am giving my lecture which then means I need to regain my train of thought. I am deathly afraid of public speaking already so regaining my track of thought is more difficult although it is getting better as I get used to being the teacher in front of the class. I have been gracious. I explained my reasoning and the reason behind it and suggested other ways if he had something he wanted or needed to tell me. I am trying to handle it calmly and not to get mad. I am not sure about my body language. The last time I just continued teaching as if nothing had happened the best I could manage. I certainly wasn't angry, because I was to focused on making sure my students understood the content I was attempting to teaching them. There's no time to be angry.