I have witnessed something similar in our dance community, even though it did not involve a pro teacher. When I just started dancing, there was a married couple who had been longtime costumers of our studio and come to the Sat social regularly. Then a new girl showed up one day and she often asked the man to dance. Because she never asked any other man, it was obvious to everybody that she was interested in him more than just dancing. Basically their romance evolved while all of us were right there watching. I bet it was so painful for the wife. Eventually they separated and got divorced. Now all three of them stopped coming to the studio, so we don't know if the man and the girl are still together. Last time when we saw the wife, she looked great, losing a lot of weight, even though she was not fat before. One can only wonder what kind of damage her husband's affair did to her self-esteem. The man and the girl behaved themselves as if nothing were wrong, and it was almost embarrassing to us. (We called the girl Charlie's courtesan behind their back.) Another strange thing is, that this girl was a resident working to be a MD, and also good-looking. The man was just an average middle class middle-aged man. We still cannot figure out what she saw in him. The man was kind of shy and a quiet man. She was the one who chased him. If she had not been so persistent, their relationship would not have gone as far as it went.