They're both trembling by the time Barry is all the way inside, and for long moments Barry is past speech, stupefied by the incredible grip of Derek's body, so hot around him. Derek's arms are the same, wrapped around him and holding him, and Barry keens, his entire body a dull roar of pleasure until Derek calls to him.

Barry looks up, his own eyes too bright as he nods, pulling back slowly, only to sink in deep once more. "I love you," he whispers, all that he can manage as he claims a part of Derek no one else has ever been worthy of before. He knows he needs to speed up eventually, to find an angle that will make Derek's eyes flare red, but Barry can't yet get past the simple revelation of his body. "This feels so good, you make me feel so good."