He loved hearing, seeing, feeling his mate like this, so wet and aroused and all of it for him. But the sounds Stiles made - he couldn't even swallow his own moans made in response, his own hips hitching, seeking out contact but only managing to fuck into the air.
Fuck, this was what his mate did to him. He growled, loudly, at the hands in his hair, the way Stiles was fucking himself onto his fingers, the third slipping it on one determined downward thrust of his hips. Inside was nothing but wet heat and if he thought, for a second, about his cock being in there, he was going to come all over the sheets instead of inside his beautiful, needy mate.
"Do it," he hissed out, the tip of his tongue tracing his finger-stretched rim. Stiles' hand was on the back of his head though, guiding, wanting, and all he needed was that panted command to pull his fingers out and replace them with his tongue. He'd be fucking happy to. Happy to listen to his mate come this way, to be tasting him, to feel that fresh bit of slick against his mouth and cheeks--
He growled again at the warning, his fingers tightening around his hips, pulling him closer as he fucked his mate with his tongue and nearly whining when Stiles did come, slick and hot and clenching. a hand left his hips, reaching down to grip the base of his cock tightly before he rutted forward and came himself. He wanted to wait, wanted to be inside Stiles when he finally did come.
Lapping him up wasn't helping matters any, but he couldn't stop either. Stiles was so wet, and it tasted so fucking good, tongue pressing inside and laving over hip until Derek was moaning nearly continuously, and he judged his mate ready to handle his fingers again. Just to make sure he was stretched enough, ready for the knot that was going to be coming. "So good for me baby, love the way you taste, love it when you come while I'm eating you out," he babbled, three fingers tracing down his thigh and slowly beginning to ease into him again. "Shhh, take these baby, open up for my fingers, want to make sure you're ready to take my cock."