Thank you all for your comments. It is very difficult when this happens and this time I was not readdy for it, I will be if future and refuse straight away, had it been small children I would have turned them away at once because of the ponds in the back garden and the stairs, so that would have been a safty issue, but 18 year olds were a bit of a shock, I didn't think 18 year olds went on holliday with thier parents !!!