If you've never been to the ballet before, I would definitely recommend going. It was, beautiful! The way they move their bodies, the costumes, the dances, the music, its all completely breathtaking.
Some people did get very dressed up, I got a little dressed up although still kept it dressy/casual. Me and my girlfriend said next time we go, we need to get one of the boxes and bring some champagne.
I didn't take any pictures of the performance as I thought that would be quite rude and as its dark everyone would have been able to see, so I couldn't even sneak one! I can tell you now though, I've never clapped so much in my entire life! If you're looking for something fun to do with a girlfriend, go see the ballet! Although I was surprised to actually see quite a few men there! ...I would love to go see the Nutcracker next!