If it was me residing in your shoes I would wear my kilt. I think it is wrong for him to basically threaten you with a bad grade because of wearing a kilt.

""he isn't the judge in this case yet he will hold me in contempt of court for "screwing around by intentionally being a smart ***"" I cannot begin to fathom how wearing a kilt could fall under screwing around. I believe I personally would be having a conversation with the school administrators and the teacher. Make sure you include both so you can show that you are not looking to get laughs, and that you are proud of your heritage.

Just my $.02, I will now step down .