Need more info to your story.
Ahh, I'm sorry if your partner cheated on you (from the title of your post) and married someone of this nature. I know that I have standards for people and a sex employee would not be someone I'd ever picture anyone I care about being with. People are people and maybe the older massage hooker as you call her has some other attributes he admires. Doesn't matter to you though if he cheated on you and went off with her. That is adultery and there is no way to make that feel better. Very sorry if you are going through this. Agree with londres that more details might be helpful to better understand the situation and offer help to you. good luck and hugs