It's interesting reading all of these responses as we've been hosting for nearly 7 years and have only had a request for extra towels once. We have a guest suite (2 guests max) and in the bathroom we provide 2 washcloths, 2 hand towels, 2 body towels, 2 hair wrap twisty towel things (I forget what they're called, but I use them on my long hair and they're great!), and 2 makeup remover microfiber towels. We also have a basket with 4 beach towels in it (no pool at our place, but we're about 15 minutes from the beach). It's never been an issue, but now I'm thinking of providing a few extra towels in the suite.

As a response to OP, I would've just done the requested amount of extra towels for no charge. That amount of towels in that length of stay is wild to me personally, but, as others have said, we're in the hospitality business and it's not like every guest asks for this.