I'm feeling a bit bad about it because I told DP about it and he says he wouldn't have done it. This child (aged 3) was ordering me to move away from climbing frame (where I was standing helping DS) so she could climb down. I'm so used to reminding DS (who also has a bossy tendency) that I just said "Please!" in that slightly reprimanding tone you do (well I do...) She said please in a tiny voice so I then moved.
There is a bit of a backstory in that this child is rarely told "no" or made to do anything she doesn't want to do (eg get off swings for other people to have turn), which can be a bit frustrating when I'm trying to teach DS manners and sharing. So I was probably a bit wound up to start with. I could feel my friend looking at me but didn't meet her eyes and the moment passed. I feel she probably does feel criticized by me. But OTOH should I let her DD boss me around for the sake of our friendship?