Ballet is no more femine than, say, basketball. Truth be told, most teachers tend to feminize this form of dance because they usually don't have many guys in their class, so they stuck in a rut of making everything really pretty. I can't tell you how often I hear them saying "pretend you're wearing a big tutu, now reach out and..."

What you have to do is masculanize (is that a word?) the dance and remind them that men dance differently. You can be graceful and not effeminate. As a matter of fact, it really looks horrible when guys try to dance like the girls, it just looks wrong because our bodies are made different and it comes across rather bitterly.

As for tights, you don't have to wear them. Heck, I rarely wear them to dance class myself. The other women don't want to see you in them, the teacher probably doesn't either, and most guys would rather not wear them. The only exceptions are teachers who expect professional unifroms (rare nowdays), or when rehearsing for a show. Your GF should know better.

-Komo