Derek grinned, and pressed his lips against Stiles' skin in approval at his reaction. "Good boy," he praised again, slowly pulling the dildo back before pressing deeper, falling into a comfortable rhythm as he fucked the boy with the toy.
"Yeah, you'll like what I give you," he murmured, teeth sharp against the boy's skin, leaving behind bruises that he soothed away with soft kisses. "You'll beg for this, too, beg for anything to fill that slutty hole."