I love ballet so much! but....?

In all honesty, I think most people would think that it's really cool that you and your dad share a common interest like that. And I know you think it would be embarrasing, but I bet a ton of the kids in your cl will think that it's cool that he used to be a good dance. You're all dressed like that, and he's a dancer too, so it's not all that different, except for the fact that he's your dad. I know you may think it's embarrasing, but you should try to be proud. Remember that people's parents are only wearing sweats and tee shirts because they've never been great dancers and whatever, not because it's weird to. And if you ditch, not only will he wonder why you're not going, but the people in your cl will wonder why you didn't go. Also, even if he was embarrasing, EVERYONE has parents that are embarrasing at times. You wouldn't be alone and anyone who wasn't understanding would just look like an idiot.