I don’t know what laws apply on the Moon, but thanks to ITAR, Starship probably won’t be able to launch from outside the United States, which means any actual moon travel is going to be governed by US and Florida and/or Texas law. Neither of those states have legal prostitution, and while I’m not a legal expert, I suspect knowingly ferrying prostitutes to the moon might be considered a form of human trafficking. They shut down Backpage for less.