I think my reply might become one of the following:

"You can call me 'sir'. That's all you need be concerned with."

"Am I free to go?" --> followed up with complaint and visit to attorney if the answer is no, since TSA is not permitted to detain people

"I choose to invoke my Constitutionally protected right to not speak. This does not in any way indicate my non-compliance with formally established procedures as outlined by your agency." --> If taken to the "wise guy timeout" room as a result, this phrase will be the only thing that is said, along with "Am I free to go?" and "I demand to speak with an attorney".

I realize that most won't bother to give TSA a hard time over this, and that's OK. It just makes all the more fun for those of us who want to exercise the power we have over TSA to give them a hard time.