Who do I pay, and how?

You enter your card once, when you book or request. On a request it is held rather than charged, and becomes a charge the moment the owner approves — there is no second visit and no second payment. On a listing where the button says “Book now” there is no approval step and it goes through straight away. Either way, the owner is paid directly.

The service fee is added on top of the owner's price and shown as its own line on the same payment, before you pay.

Either way, you will never find a charge you weren't shown first.