Those words are like lightning against Bucky's spine, causing him to thrust even harder, deeper, feeling his cock drag against Sam's clenching hole. He's got both hands at Sam's waist, now, holding "You feel so good," he tells the prince, as his hips begin to stutter in their rhythm. A few more thrusts and Bucky groans, getting as deep into Sam as he can once his orgasm overtakes him. "I would knot you if I could. Fill you up. Hold you down."

He feels the prince paint his chest with cum again and grins, even though he doesn't pull out immediately. Keeps Sam from being able to pull away. He wants Sam to have him for as long as possible.