@Julie143
It sounds like your guest has gotten into the habit of drinking bottled water, but that doesn't necessarily mean you have to provide it for them free of charge. As a couple of others have said you could try re-iterating that you offer fresh (and free) drinking water from both the tap and fridge filter -having ice on tap is an added bonus!
I would certainly play on your green credentials, the planet is in enough of a mess as it is without clogging it up with more used bottles, etc. Hopefully, your guest will understand where you are coming from.
Pleasing guests can be a challenge, it's worth going that extra mile for rave reviews (but only if it doesn't come at too much of a price)! I try and make my guests feel welcome by adding a few personal touches, such as:
Homemade cookies
I include all ingredients on a label to counter issues with food allergies/intolerance. Luckily I love baking (and it's an excuse to eat cookies)!
A comprehensive welcome book
I provide details as to what's on locally and offers discount codes for local attractions (I have negotiated a few of these with local businesses - I'm a fan of you scratch my back and I'll scratch yours)! I found this helpful if you fancy taking a look: https://www.airgms.com/airbnb-welcome-book/
Extra cosy throws / cushions
I like my guests to chill out and feel at home.
A Handwritten card / note
I always just leave a little card with my cookies to say have an amazing time and remind them of my contact number should they need anything.
Guests like to feel special in my opinion! But would I offer bottled water - nope!
Happy Hosting!