We've just received an enquiry via one of our listing sites from the same person, for the same dates which they enquired about 3 weeks ago via another listing site. I understand people can forget, but our property is distinctive, so I just find it a bit odd. What I also find odd is that; they haven't managed to book something in that intervening period, which is what I assumed they must have done as they didn't book with us.
I simply replied in the same way as before without mentioning that they had already enquired. Wonder if they'll blush when they realise and wonder if they'll book?