I signed up for yoga class because of a foot fetish
Are feet the only reason for you joining the class, or are there other reasons also?
Just because my feet are so sexy they are too much to handle alone.
Well yoga is good exercise so it is good you are taking advantage of the class. There's typically nothing wrong with a fetish, but signing up for a class so you can stare at other people's feet may creep them out.
Oh good. I'm feeling better now.
If you're only appreciating your own feet then that is fine, but try not staring at other people's feet. You may scare them and they won't want you at their yoga class anymore.