Our neighbours are very unpleasant to us. We share a large drive, which they own. However in the needs it says that we have an allocated parking space on part of their land. They also have their own adjacent allocated space, and our other neighbours have one next to that. They don't park in the other neighbours's space but have recently started allowing their guests to use ours. This isn't a massive problem for us as we have another potential space nearby. However we've politely asked them to seek permission from us first in case we need to use the space on that occasion for our own visitors. They've spat the dummy out, sent a very combative message in reply, describing it as a 'grey area'. They seem to think because it's their land that they can do pretty much what they like. It's not a grey area, is it?!