Most of the time, the growl wasn't even a conscious thing. He didn't know he did it. Sometimes he did it deliberately, because he knew what effect it could have. Sometimes it was a reaction, to things like realising Candy was fingering herself at the same time she was going down on him.
The chair confined his movements somewhat, but he threw his arms back and over his head, gripping the back of the chair. Pleasure raced through him, white hot and burning up and down his spine, curling in his gut, right to his very core. He gasped and growled, alternately, as his hips spasmed against her.