>You would say that hitting on women is not appropriate in gym. So which places are okay to hit on women? My female friend told me that it's okay to hit on her in yoga classes.

Well, she said that, some other woman might say otherwise.

In general, this is mostly a charade. Being accepted is mostly about being the right person and having the right timing, not about whether space X or Y is appropriate or not. People have hooked up succesfully in every kind of place, including work (heck, especially there), hospitals, and funerals.