Is it still stealing if you tell the person you're going to take something from that you're taking it?

My co-workers and I were having a light discussion about this. One lady has chocolates in her office and a few of us will go in and say, “I’m going to steal a chocolate from you.” Another girl has pretty much the only reliably functioning stapler in the area she works. So people in that area will say, “I’m going to steal your stapler” and then take it back to their desk to use. Now, here’s the question: Is it only stealing when you don’t intend to bring it back? Obviously, the chocolates aren’t going to be returned. The stapler could be, but it never is. The way we figured it is that we can’t call it borrowing if the items aren’t returned, but if you’re outright telling the person you’re taking something from them then is it still stealing, or does the act of stealing imply that it’s stealthily taken?