Caught red handed.

"Well Johny get out here and play some volley ball," Coach Luna calls to you.
Caught off gaurd you jump to your feet not noticing you had a boner. while it eluded you sight till now you had sudenly becoe aware of your condition and so had the rest of the class. "Johny do you need to go to the restroom," Coach Luna asked you. "Yes mam," you relunctantly reply. Trying to hide your massive errection you head to the showers. You strip down and take a cold shower trying to rid your self of the boner. It does not help.
Time passes as you remain in the shower and the boys of your class come and go. As the ball rings you hear a voice. " Are you alright in there?" It was coach Luna. "No mam ," you reply. "Whats the problem," she inquires. "It wont go down."