Typically in spas, nudity, if any, happens at the end of the session. In this day and age, getting a nude massage in a spa “from the get go” is rare unless you get to know a particular masseur through repeat business. Also, certain spas with private rooms and doors that lock are more conducive. And as @NYMassageAddict suggests, shower rooms may amp the opportunity.
As per forum guidelines, we will PM to discuss details on specific spas and spa masseurs.