My guest was my DB who, when he last visited over 18 months ago, was deliberately obnoxious and cruel to me. I had been dreading his visit for days.
As he walked in the door he was being aggressive and swearing in front of my 3 DC's - loudly complaining about my neighbour whilst the door was still open. My heart sank as all my worries were realised.
I was initially polite asking him to "please" move his car (there is a history of ill-feeling in the village - all houses have their predecided unofficial spaces), I explained he would be creating a problem for me if he didn't move his car and he refused. I then used his own language back at him and gave him an ultimatum. He left.
My DH who had been upstairs came down to see what was going on and then went to apologise to our neighbour who said that my DB had been rude. BTW this neighbour is lovely.
BTW everyone in the village respects the space in front of each others houses despite it being a public road (very rural) and asks guests to park in "guests spaces". The benefits are that with a car full of children and shopping I can always park in front of my house. Obviously it doesn't always work and not everyone agrees with it.
Whatever the circumstances, if I had been asked by someone (when there were other spaces available) to move I would have done so without question. It's just polite. I don't need to know why unless they wish to share it with me. If someone tells me that something I am doing will cause them problems in their neighbourhood I would do my best to remedy the situation - whether I thought it was nonsense or not. They have to live there - I don't.