I remember when I first started working out, I had a trainer that was hot (female), wife got wind, that Windy was my trainer, good lord, how many questions did I get from W about her, and all I said was yeah she is hot, well, gotta run, meeting Wendy again at 10.
When she and I were dating, she came running back to me after she found out that I was dating a hot girl, just something in a woman that cannot get beaten by another woman.
I would not go on a "date" as I think she is looking for justification for her actions, but I would make her think that I have found someone that I am interested in, in a covert type fasion.