Grant stared at he for a moment. What he needed to get from her completely forgotten at the accusation of Nazi.
"Wait, what, Nazis!?"
That wasn't what he was doing. Nazi's were hateful, prejudiced, concentration camps types. He wasn't a Nazi. He didn't particularly hate anyone, he didn't care about skin color, or racial profiles, or any of that, and he certainly wasn't putting anyone in a concentration camp. A Nazi was someone evil; and while Grant had done some not nice thing, and could do some not nice things, and while part of him was not surprised at Skye's response - because, after all, he had known there aspects of who he was she wouldn't like - he wasn't evil. If anything, the reason he'd done most of what he had done was because Garrett had asked him to. The man who had been a better father than his own father had needed him and so Grant had offered assistance and willingness.
Raina had been right, even, that he felt a twinge of regret about what he'd done to Phil Coulson. Grant knew a good man when he saw one and Coulson was a good man, but Garrett had given him so much -- an opportunity, and strength, and had offered a willingness to over-look Grant's own numerous flaws to give, and to continue to give him a chance.
To have the word thrown at him without Skye having any understanding of what he'd done, the choices that he'd had to make along the ways, the uncomfortable knowledge that even if he would be strong enough to not shirk from the task the task might not be pleasant -- was maddening and when he spoke again it was with emotion that would have been better buried, but part of him just wanted Skye to understand: "I'm not a Nazi!"