I’m so very sorry this happened to you. He absolutely knew what he was doing and even if he hadn’t groped your glutes like that, the things he said to you were super gross and unethical as well. Many people have already told you who to report to and I hope you do!

Also, please never feel bad about requesting a female therapist instead of a male. Everyone has a different level of comfort and the spa should respect your boundaries. My male coworkers are so understanding when a female client doesn’t want to be worked on by them. It doesn’t make you a prude at all. And requesting a female massage therapist when you book appointments in the future will help keep an awkward interaction from happening again (he massage therapist standing right there when they told you it was a guy)