"Turn around and place the device very gently on the chair next you. This device is way more valuable than you'll ever be slave!. And don't forget to keep your head down."
(You cautiously place place the device on the chair)
"Good. now get hard wit... Forget it, you're already hard. Well, that was quick, wasn't it slave?. Getting a bit ahead of yourself over there, are we now?. Your're rockhard.."
"I couldn't help it mistress, please forgive me mistress"
"Seems like you enjoy being locked up way more than I thought you would. Or maybe it's something else?. Anyhow, let it go soft again slave.. Tonight you'll obey my every whim. And you'll certainly won't get hard without my permission slave. That is one of the first things i'm gonna teach my new slaves. To not get aroused without my permission."
"Sorry mistress, I didn't.."
"Well then, seems like we have to wait this one out.."
(After a few minutes of complete silence, your cock is still hard, harder than before actually)