Mom's first time going to spinning and she ends up totally hooked!!

The first time Mom goes to spinning class, she ends up completely fucked, and not only her, the other woman also ends up having sex with the instructor. It's something I honestly can't understand. How can something like that happen? How can a woman end up getting fucked in a class like that? It's one of two things, friends, or you're a total slut, which might be the case, and you have a huge addiction, so the first opportunity you get doesn't even think twice...