Isaac gave a shuddering gasp, as he felt himself pushed up against the wall, and lowered onto Derek's cock. He leaned in, putting his arms over his Master's strong, broad shoulders, to give him some leverage.
"Yes," he moaned, working his hips back and forth, to try and force the shaft deeper into him, as though that were possible.
"I need you. I'm a slut, just for you Sir, just for my Master."
To an outside observer, it would have sounded like dirty talk, but there was nothing put on about Isaac's reaction. He would happily beg for Derek's cock, even as his cheeks flushed with embarrassment and arousal.