Our first ever AP arrived 2 weeks ago. She is 25. She is pleasant, competent as an AP, and is clean and tidy. So far so good. I have provided her with a document setting out ground rules, but this did not extend to "please do not help yourself to our stuff" as I assumed this was obvious.
I went out today and had to return home as had forgotten something. When I got back, I found the AP listening to her iPod using DS' ridiculously expensive headphones (Christmas present from his father). DS is very precious about these headphones and doesn't like anyone else touching them - even I don't use them! The DCs are away at their dad's this weekend so I know he did not say to the AP that she could use them.
I had to leave in a hurry as was late, so texted her afterwards saying please do not use DS' headphones as he does not like other people using them and if anything were to happen to them, I couldn't afford to replace them. I can see she has read the text, but she hasn't even replied with a quick "sorry, won't do it again".
Am I BU to think if you are living with other people it is not ok to just help yourself to their possessions? There have been a couple of other incidents where she's shown a slightly "entitled" attitude but as she is good overall I don't really know how much of an issue I should make about this, if at all.