mmmhh yessss. I can totally see Scott being the king of pre-mature knotting and not even embarrassed about it. Rabbit fucking into a warm hole, even if it’s just his new flesh light, knot always plump at the base of his cock, ready to swell at the slightest encouragement.
When the guys in the locker rooms rib him for how his jock is always so full and how pink and obvious his knot is when they shower, he just grins and bears it. I can imagine his eyes rolling up in his head, body jerking through orgasm after orgasm, creaming up the pretty hole he was allowed to rut into.
On the other hand Derek would be the most embarrassed early-knotter ever. Just whining through clenched teeth, ears burning in shame when it starts to swell after only a few hard, heartfelt thrusts. He just can’t help that he’s so sensitive!