And am back to being annoyed again

And being annoyed by the same person too.

Two postdocs in my lab started to discuss some orders they needed to do and since that person, whom made me angry so much not too long ago, was going to do the orders, he wanted to know how much the other postdoc needed. Since, I overheard the conversation, I asked what it was that they are ordering as it sounded as if it is something that I'll be needing too in my experiments. But what was the reply I got from Mr. Annoying???

"Why don't you write down your experiment plan for me so I know how much (of the chemicals) you actually need?"

Hang on a second man, what gives?

"I don't think I'll need a lot of it, well depending on your order size, that is." I said, well something like that anyway.
"Yeah still you should have your experiment plan written down, so do that and we'll see how much you need."

Needless to say, I was a bit confused. First of all, why the F*ck do I need to show him my experimental plan? He ain't my boss. Second of all, I know how much I need. I just need to know if there will be enough for me in the order too.

The other postdoc at this time came to my defense, saying I already have an experimental plan (which is true, as I had discussed this with him before since he was the expert in this field) and that my plan only calls for small usage in comparison to his experiment. So, I could potentially just use some of his when they order in. No need to put in an extra order.

Okay, so problem solved. But I just can't get over the arseyness of Mr. Annoying. He didn't ask the other postdoc to write his experimental plan for him to see. I have this feeling that I'm only being treated this way because I'm the bottom of the tier in this lab.