This has to be some sort of divine punishment.
After all your travels. Your time together. After his people's victory in the battle of Hoover Dam. After he fucking trusted you, all this time...
There were signs, that's the worst part. And Boone is the best at picking those apart. He can tell who was a Legion dog, a spy, just from the way they walk. The way they talk. He can always recognize it.
And he just forced himself to be blind to you.
You fought like those pieces of shit. You talked weird. You understand the poor latin the Legion speaks. You moved like them. You didn't drink or use drugs, meds...even if you didn't know why you followed that rule, or so you said.
A part of himself wants to believe that the bullet Benny planted in your head made you forget your mission as a frumentarius, adopt courier 6 as your identity, that it all had been genuine. And he knows deep down that's the truth. Why else had you brought victory for the New California Republic? destroyed the legion?
He swallowed the bile that the urge to kill every last one your kin made raise. Because he knows what kind of person you were before being Courier 6.
But he can't anymore. Not when you seem to have remembered. Not when he just caught you back in the Fort, wearing one of those stupid fucking dresses while you dig a grave, for who, a legionnaire? him? fuck...a part of him hopes it's for him. He feels like ignoring your nature was betraying Carla...
And when your head looked up you were met with his scope. And you knew he would've shot you if it wasn't for your time together, for how long you were akin to friends. "Talk" he demanded, but he knows what you'll say.