Isaac was good at taking cock, that much he knew. Even when his former Master had berated him with all of his shortcomings, there had never been any doubt of what he was good for. Fucking, sucking cock, being used. At first Isaac had been ashamed of how much he had enjoyed those things, but Derek had taught him that they weren't always bad things. And he had betrayed that.
"Yes," he moaned, tears starting to drip, unseen, down his cheeks. Despite his shame, Isaac's cock was hard and it bobbed in front of him, hitting against the flatness of his stomach, with the rougher thrusts.