The legality of a massage therapist refusing to accept male clients based solely on their gender can vary depending on the jurisdiction and the applicable laws in that region. In many places, discrimination based on gender is generally against the law, and businesses, including massage therapists, are expected to provide their services without discriminating on the basis of gender, race, religion, or other protected characteristics.
In the United States, for example, Title II of the Civil Rights Act of 1964 prohibits discrimination in places of public accommodation on the basis of race, color, religion, or national origin. Some state and local laws also extend these protections to include other characteristics such as gender and sexual orientation.
However, there may be exceptions in specific circumstances. For instance, if a massage therapist operates a business out of their private residence and does not hold themselves out as a public accommodation, they might have more leeway regarding who they accept as clients. Moreover, there could be situations where a therapist specializes in certain types of massage therapy that are only suitable or requested by clients of a particular gender.
It's essential to research the specific laws and regulations in your area or country to understand the rights and responsibilities of massage therapists and clients. If you encounter a situation where you believe you have faced discrimination, it's recommended to seek legal advice or report the incident to the appropriate authorities or organizations that handle such complaints.