Hello Boyz!

I received this e-mail from one of my friends:

So you're next to the Headmaster, right, at the House Play. Your 17 year old son's tutor has expressed warm support for his application to become a prefect. Your son appears on stage. Four young boys acting as mincing exam inviligators have paraded around snatching exam papers and other forbidden items from exam candidates. The music, The Stripper, swells to a crescendo. They surround your son, dressed as a schoolmaster,who marches proudly to the very front of the stage. To the final chord of The Stripper, and in perfect time, your prefect son rips off his trousers to reveal himself, in all his glory, clad in suspenders and fishnets.

What is the correct answer to the headmaster's question- "And which one is your son?"