@Steve22 Hi there Steve.....Welcome to Airbnb and the Community Forum. I hope your time hosting with Airbnb will be as wonderful as mine (and many other hosts) has been.
Re this booking of yours. Steve, don't go anywhere near it!!! Anyone who wants to work outside the organisation they have used to get in touch with you will probably pose a risk to you in some way.
We open our homes to guests, we bring them into our own personal environment and, for that reason, we brush aside little trivialities because we are eager to please them. Many guests are aware of this and use it to their advantage. Children are the most common problem! On many occasions guests don't tell a host they will be bringing small children. As far as the host is concerned the guest regards their child as...... a suitcase, or some other belonging that just happens to travel with them. Similar issues arise where pets are concerned. In a lot of these instances, once the guests booking has been accepted by the host the guest feels they have the upper hand and the host will go along with whatever they require! Just a month or so of reading questions on this forum will tell you that this happens over and over again. Some hosts actually have a set of rules they require a guest to read, aknowledge and accept in writing before they will confirm a guest booking.
Now Steve, these are examples of people who are eager to work within the system...just bend it's rules a bit! But when someone wants to abandon the safeguards that this platform offers then it is a sure bet, there will be trouble.
Steve, decline this one, give your reasons for declining, and there are situations where Airbnb will accept that, and wait for the next guest booking.....Good luck....cheers.....Rob