After all these betrayals, Arthur can't stop wondering: who will betray me next?
That might be depressing, but it becomes a fun game between him and the knights.
Gwaine: oh that's easy, if I were to betray you, it's because i had to choose between you and Merlin.
Leon: i would only betray you, if i was brainwashed by a sorcerer, sire.
It goes on like that. And then they begin tossing ideas about Merlin, when he's not there.
Arthur: *joking* he would totally betray me, as soon as the next sorcerer threatens his life. He's a coward.
Everybody laughs: we all know that's not true, Sire.
Arthur: well, then, if i lifted the ban on magic he would surely-
Lancelot: nope, don't even go there. *In his head*: He would probably marry you if you did that *
Arthur: okay, what if i was being especially rude to him from now on and put him in the stocks and-
Gwen: yeah no. That's hardly different from normal. He would never.
Arthur: what if he was brainwashed????like leon said?
Leon: *nervous* actually that did happen once and he failed to put even a scratch on you.
Arthur: what? *Continues staring at Leon in utter confusion*
Leon: i kinda.... *Accidentally* gave him a weapon to kill you because i thought it was a joke? *Shrinks into himself*
Arthur: we're definitely going to talk about that later....
Anyway. So, what if I killed his best fr- no shit, Will did actually die for me. If i killed his girl- no Merlin has no love interest. What if I killed his dad? No wait, the guy is dead too.
Gwaine: wait.... I'm not Merlin's best friend??????
Arthur: come on guys, help me out! When would Merlin betray me? If I asked him to? No, if I ORDERED him to.
Gwen: merlin never listens to your orders.
Arthur: what if he was bribed? What if he was tortured?
Lancelot: that has all happened, Sire
Arthur: *so fucking done* the fuck, WHEN?!?!?!
So wait, what if Merlin had magic!!!! Magic corrupts! He would totally-
Everyone collectively: NO
Gwaine: so i guess we all knew but that guy over there, hmm?
Arthur: what- what are you guys talking about?
Gwen: *sighs* you know what Arthur. We were all wrong. We would all betray you, if you betrayed Merlin.
Arthur: *feels betrayed already* guys, if merlin had magic- i would have to kill him! Surely HE would betray ME first, wouldn't he?
Lancelot: Sire, with all due respect. If you sentenced Merlin to death, he would light the pyre himself.