I rented my bedroom out through a Web-based vacation-rental service. It became apparent that the guest and I had some sexual chemistry. The first night I slept on my futon in another room. The next day we “slept” together — this was entirely consensual and not solely instigated by me — in my bedroom. Do I refund her the rental fee and, if so, for one or both nights? NAME WITHHELD, SAN FRANCISCO

Congratulations on finding yourself in one thoroughly modern muddle. By helping people open their home to strangers and trade money for the intimacies of domestic life — some apparently more intimate than others — these rental services can make for great bargains and great ethics questions.

Keep your guest’s fee and you risk offending her by valuing the money more highly than your encounter. Return the fee (or split the difference) and you risk placing a dollar value on the encounter — retroactively making it sex for hire.

Image Credit... Illustration by Matthew Woodson

It’s an example of the difference between etiquette and ethics. Etiquette requires you to do what is polite, namely refund the money. But ethically, the issue is whether you are using money to pressure someone for sex (or vice versa). The best way to keep that from happening is to keep the two realms separate. If the terms of the rental were not explicitly subject to future hook-ups, then the fact that one took place is of no bearing. Keep the money.