Percival was out on patrol when he first heard the noises, he heard rustling coming from up ahead and thought he should check it out, as he was on guard duty, it would be irresponsible not to.
He moved through the trees and came across something he didn't expect, Prince Arthur of Camelot, fucking his servant into a tree.
Of course the men had all debated about the two's relationship, but Percival never thought there'd be any truth in it, he stopped and saw the sight before him, in all honesty it wasn't awful, the two looked quite good together, even though their torsos were hidden, Percy could tell both of their asses and in particular Arthur's legs were very well toned.
Percival gawped for a while until he began to notice the tightness in his trousers, he couldn't help it, watching the two go at it like dogs made him painfully hard, he felt so wrong, but he had to touch himself, Percy decided to hide behind a bush and quietly pulled down his trousers and let his enormous erection spring to life. It was already wet and fully aching, his balls were hanging and warm, his fingers entwined around his thick shaft and he began to pump, he watched intently, from where he was, he was right behind the two men, he watched as Arthur's toned arse peeked out from underneath his chainmail, and saw how the muscles tensed and thrusted into Merlin's backside.
He could hear their moans, see Arthur's thrusting arse, he was just able to make out both of their balls sacks, dangling beneath them, they looked so erotic. Percy was close, he could feel the familiar warmth in his belly that told him he'd soon be covered in cum, he stopped briefly as he saw the two finish up, he saw how Arthur thrust one last time into Merlin, before bending down and licking his load from Merlin's hole.
That was it for Percival, with one final tug me looked down and shot a thick, white load straight up his body, hitting him square in the face, twice. Once he had finished, he began to lick the cum from off of his face and hands, burying his cum covered groin back into his trousers, he scurried off back into the woods, face sticky, cock satisfied, with the mental image of Prince Arthur's arse in his mind forever.