Derek seizes so tightly that Barry almost fears it's too much, but then Derek's come splashes hot between them, again and again until Derek is half slumped and Barry's vibrations have slowed. He isn't strong like Derek, but Derek's permission is all Barry needs to speed Derek onto his back, his legs hitched high around Barry's waist so Barry can sink into him again the way his body's screaming for.

"That was so good," he murmurs, fucking Derek with slow, deliberate strokes. "I love the way you look when you can't hold back."